Category: Class 9

Balbharti Maharashtra State Board Class 9 Science Solutions Chapter 5 Acids, Bases and Salts Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 9 Science Solutions Chapter 5 Acids, Bases and Salts

Class 9 Science Chapter 5 Acids, Bases and Salts Textbook Questions and Answers

1. Identify the odd one out and justify.

(a) Chloride, nitrate, hydride, ammonium
Answer:
Ammonium is the odd one out as it is a basic radical and rest all are acidic radicals. Generally, basic radicals are formed by the removal of electrons from the atom of metals such as Na⁺, Cu²⁺. But there are some exceptions, such as NH₄⁺.

(b) Hydrogen chloride, sodium hydroxide, calcium oxide, ammonia
Answer:
Hydrogen chloride is the odd one out. It is acidic and rest all are basic.

(c) Acetic acid, carbonic acid, hydrochloric acid, nitric acid
Answer:
Carbonic acid is the odd one out. It is a dibasic acid and rest are all monobasic acids.

(d) Ammonium chloride, sodium chloride, potassium nitrate, sodium sulphate
Answer:
Ammonium chloride is the odd one out, as it is made up of a strong acid and weak base and rest all are formed from strong acid and strong base.

(e) Sodium nitrate, sodium carbonate, sodium sulphate, sodium chloride
Answer:
Sodium carbonate is the odd one out, as it is made up of a weak acid and strong base, and rest all are formed from strong acid and strong base.

(f) Calcium oxide, magnesium oxide, zinc oxide, sodium oxide.
Answer:
Zinc oxide is the odd one out, as it is an amphoteric oxide, and rest all are basic oxides.

(g) Crystalline blue vitriol, crystalline common salt, crystalline ferrous sulphate, crystalline sodium carbonate.
Answer:
Crystalline common salt is the odd one out, as it does not contain water of crystallisation. It is an ionic compound and ionic compounds are crystalline in nature and rest all have their crystalline structure because of their water of crystallization.

(h) Sodium chloride, potassium hydroxide, acetic acid, sodium acetate.
Answer:
Acetic acid is the odd one out. It is an acid, the rest are all salts.

2. Write down the changes that will be seen in each instance and explain the reason behind it.

(a) 50ml water is added to 50ml solution of copper sulphate.

Answer:

• Copper sulphate solution is blue. It is a concentrated solution.
• When 50 ml of water is added to this concentrated solution, it becomes a diluted solution.
• The intensity of the blue colour is now different in this homogenous mixture.

(b) Two drops of the indicator phenolphthalein were added to 10ml solution of sodium hydroxide.

Answer:

• Sodiumhy droxide is a base and phenolphthalein is a synthetic indicator.
• Sodium hydroxide solution will turn pink if phenolphthalein is added to it.
• It is a test for identifying bases.

(c) Two or three filings of copper were added to 10ml dilute nitric acid and stirred.
Answer:
When copper metal reacts with dilute nitric acid, the metal does not displace hydrogen from the acid like reaction with other metals. Instead the reaction produces nitric oxide, (NO).

(d) A litmus paper was dropped into 2ml dilute HCl. Then 2ml concentrated NaOH was added to it and stirred.
Answer:
Blue litmus Paper:

• HCl is hydrochloric acid, so the blue litmus turns red.
• When equal amount of NaOH is added the colour again changes to blue and remains the same.

Red litmus paper:

• Red litmus paper shows no colour change in hydrochloric acid.
• When some amount of NaOH is added the colour changes to blue initially but when the amount of NaOH is sufficient the blue colour dissappears.
• Equal amounts of HC1 and NaOH results in the formation of NaCl, a salt, and the solvent water. This reaction is called the neutralization reaction.

(e) Magnesium oxide was added to dilute HCl and magnesium oxide was a added to dilute NaOH.
Answer:
(i) Magnesium oxide + dil HCl.
This is a neutralization reaction. Magnesium oxide is an insoluble base, it reacts with dilute HCl to produce a soluble salt MgCl₂ and water H₂O.
\(\mathrm{MgO}_{(\mathrm{s})}+2 \mathrm{HCl}_{(\mathrm{aq})} \longrightarrow \mathrm{MgCl}_{2(\mathrm{aq})}+\mathrm{H}_{2} \mathrm{O}_{(n)}\)

(ii) Magnesium oxide + NaOH.
No chemical reaction takes place between magnesium oxide and sodium hydroxide.

(f) Zinc oxide was added to dilute HCl and zinc oxide was added to dilute NaOH.
Answer:

• Zinc oxide reacts with dilute hydrochloric acid to form zinc chloride and water. It is a neutralization reaction.
  \(\mathrm{ZnO}_{(\mathrm{s})}+2 \mathrm{HCl}_{(\mathrm{aq})} \longrightarrow \mathrm{ZnCl}_{2(\mathrm{aq})}+\mathrm{H}_{2} \mathrm{O}_{(\mathrm{l})}\)
• Zinc oxide reacts with sodium hydroxide to form sodium zincate and water.
  \(\mathrm{ZnO}_{(\mathrm{s})}+2 \mathrm{NaOH}_{(\mathrm{aq})} \longrightarrow \mathrm{Na}_{2} \mathrm{ZnO}_{2(\mathrm{aq})}+\mathrm{H}_{2} \mathrm{O}_{(\mathrm{t})}\)

(g) Dilute HCl was added to limestone.
Answer:

• When hydrochloric acid is added to limestone, carbon dioxide is liberated. Limestone is calcium carbonate.
  CaCO₃ + 2 HCl → CaCl₂ + CO₂ + H₂O
• Carbon dioxide is prepared in the laboratory using these chemicals.

(h) Pieces of blue vitriol were heated in a test tube. On cooling, water was added to it.
Answer:

• On heating, the crystalline structure of blue vitriol breaks down to form a colourless powder and water is released.
• This water is part of the crystal structure of blue vitriol.
• It is called water of crystallization.
• On adding water to the white powder, a solution was formed which has the same colour as the copper sulphate salt solution.

(i) Dilute H₂SO₄ was taken in an electrolytic cell and electric current was passed through it.
Answer:

• If pure water is used in the electrolytic cell, current does not flow even on putting on the switch.
• Pure water is a bad conductor of electricity. Dilute H₂SO₄ is acidulated water.
• The electrical conductivity of water increases on mixing with strong acid or base in it due to their dissociation and electrolysis of water takes place.
• H₂SO₄ is fully dissociated in aqueous solution. \(\mathrm{H}_{2} \mathrm{SO}_{4} \longrightarrow 2 \mathrm{H}^{+}+\mathrm{SO}_{4}^{2-}\)
• H₂O is a weak electrolyte and is only slightly dissociated \(\mathrm{H}_{2} \mathrm{O} \longrightarrow \mathrm{H}^{+}+\mathrm{OH}^{-}\)
• During electrolysis, the hydrogen ions migrate towards the cathode and are discharged there.

[H+ ions gains electrons and are converted to hydrogen gas]
\(2 \mathrm{H}^{+}+2 \mathrm{e}^{-} \longrightarrow \mathrm{H}_{2(\mathrm{~g})}\)
Cathode reaction:
\(2 \mathrm{H}_{2} \mathrm{O}_{(\mathrm{i})}+2 \mathrm{e}^{-} \longrightarrow \mathrm{H}_{2(\mathrm{~g})}+2 \mathrm{OH}_{(\mathrm{aq})}^{-}\)
Anode reaction:
\(2 \mathrm{H}_{2} \mathrm{O}_{(\mathrm{l})} \longrightarrow \mathrm{O}_{2(\mathrm{~g})}+4 \mathrm{H}_{(\mathrm{aq})}^{+}+4 \mathrm{e}\)

• For every hydrogen ion discharged at the anode, another hydrogen ion is formed at the cathode.
• The net result is that the concentration of the sulphuric acid remains constant and electrolysis of water is overall reaction. \(2 \mathrm{H}_{2} \mathrm{O} \longrightarrow 2 \mathrm{H}_{2}+\mathrm{O}_{2}\)
• The volume of the hydrogen gas formed near the cathode is double that of the oxygen gas formed near the anode.

3. Classify the following oxides into three types and name the types.
CaO, MgO, CO₂, SO₃, Na₂O, ZnO, Al₂O₃, Fe₂O₃
Answer:
There are three types of oxides : Basic oxides, Acidic oxides and Amphoteric oxides.

Basic oxides	Acidic oxides	Amphoteric oxides
CaO	CO2	ZnO
MgO	SO3	Al2O3
Na2O
Fe2O3

Generally metal oxides are basic in nature.
Exception : Al₂O₃ and ZnO are amphoteric oxides.
Generally non-metal oxides are acidic in nature.

4. Explain by drawing a figure of the electronic configuration.

a. Formation of sodium chloride from sodium and chlorine.
Answer:

b. Formation of a magnesium chloride from magnesium and chlorine.
Answer:

5. Show the dissociation of the following compounds on dissolving in water, with the help of chemical equation and write whether the proportion of dissociation is small or large.
Hydrochloric acid, Sodium chloride, Potassium hydroxide, Ammonia, Acetic acid, Magnesium chloride, Copper sulphate.
Answer:
(a) Hydrochloric acid (HCl)

• \(\mathrm{HCl}_{(g)} \frac{\text { Water }}{\text { dissociation }}>\mathrm{H}_{(\mathrm{aq})}^{+}+\mathrm{Cl}_{(\mathrm{aq})}^{-}\)
• Hydrochloric acid is a strong acid, as on dissolving in water, it dissociates almost completely and the resulting aqueous solution contains mainly H ions and the concerned acidic radical.
• The proportion of dissociation is large.

(b) Sodium chloride (NaC1)

• \(\mathrm{NaCl}_{(s)} \frac{\text { Water }}{\text { dissociation }}>\mathrm{Na}_{(\mathrm{aq})}^{+}+\mathrm{Cl}_{\text {(aq) }}^{-}\)
• When an ionic compound begins to dissolve in water, the water molecules push themselves in between the positive and negative ions of the compound and separate them from each other.
• The proportion of dissociation is large.

(c) Potassium hydroxide (KOH)

• \(\mathrm{KOH}_{(n)} \frac{\text { Water }}{\text { dissociation }} \mathrm{K}_{(\mathrm{aq})}^{+}+\mathrm{OH}_{(\mathrm{aq})}\)
• Potassium hydroxide is a strong base, as on dissolving in water, it dissociates almost completely and the resulting aqueous solution contains mainly OH⁺ ions and the concerned basic radical.
• The proportion of dissociation is large.

(d) Ammonia (NH₃)
(i) \(\mathrm{NH}_{3(\mathrm{~g})}+\mathrm{H}_{2} \mathrm{O}_{(\mathrm{n}}-\frac{\text { Water }}{\text { uissociation }}>\mathrm{NH}_{4 \text { (aq) }}^{+}+\mathrm{OH}_{\text {(aq) }}^{-}\)
(ii) Ammonia dissolves in water to form NH₄OH (ammonium hydroxide). NH₄OH does not dissociate completely as it is a weak base. The aqueous solution contains a small proportion of OH^– ions and the concerned basic radical along with a large proportion of undissociated molecules of the base i.e. NH₄OH.
(iii) The proportion of dissociation is small.

(e) Acetic acid (CH₃COOH)

• \(\mathrm{CH}_{3} \mathrm{COOH}_{(l)} \frac{\text { Water }}{\text { dissociation }} \mathrm{CH}_{3} \mathrm{COO}_{(\text {aq) }}+\mathrm{H}_{(a z)}+{ }^{+}\)
• Acetic acid is a weak acid, on dissolving in water it does not dissociate completely, and the resulting aqueous solution contains H⁺ ion and the concerned acidic radical in small proportion along with large proportion of the undissociated molecules of the acid.
• The proportion of dissociation is small.

(f) Magnesium chloride (MgCl₂)

• \(\mathrm{MgCl}_{2(\mathrm{~s})} \frac{\text { Water }}{\text { dissociation }}>\mathrm{Mg}^{2+} \text { (aq) }+2 \mathrm{Cl}^{-} \text {(aq) }\)
• Magnesium chloride dissolves in water and forms magnesium ions and chloride ions. When an ionic compound begins to dissolve in water, the water molecules push themselves in between the ions of the compound and separate them from each other.
• The proportion of dissociation is large.

(g) Copper sulphate (CuSO₄)

• \(\mathrm{CuSO}_{4(s)} \frac{\text { Water }}{\text { dissociation }}>\mathrm{Cu}_{(\mathrm{aq})}^{2+}+\mathrm{SO}_{4}^{2-}\)
• When Copper sulphate is dissolved in water it forms copper ions and sulphate ions. When an ionic compound begins to dissolve in water, water molecules push themselves in between the ions of the compound and separate them from each other.
• The proportion of dissociation is large.

6. Write down the concentration of each of the following solutions in g/L and mol/L.

a. 7.3g HCl in 100ml solution
b. 2g NaOH in 50ml solution
c. 3g CH₃COOH in 100ml solution
d. 4.9g H₂SO₄ in 200ml solution
Answer:
To find : The concentration in g/L.
Solution:

7. Obtain a sample of rainwater. Add to it a few drops of universal indicator. Meausre its pH. Describe the nature of the sample of rainwater and explain the effect if it has on the living world.
Answer:

• pH of rain water is 6.5 that means rain water is slightly acidic.
• When we add universal indicator to rain water it turns orangish red, indicating pH value is between 0 to 7, which tells us that rain water is acidic in nature.
• Most of the plants grow best when pH of soil is close to 7. If the soil is too acidic or too basic, it affects plant growth.

8. Answer the following questions.

a. Classify the acids according to their basicity and give one example of each type.
Answer:

• Basicity of acids : The number of H⁺ ions obtainable by the dissociation of one molecule of an acid is called its basicity. The acids are classified as monobasic, dibasic and tribasic acids based on the number of H⁺ ions present.
• Examples of monobasic acid : HCl, HNO₃, CH₃COOH
• Examples of dibasic acid: H₂SO₄, H₂CO₃
• Examples of tribasic acid: H₃BO₃, H₃PO₄

b. What is meant by neutralization? Give two examples from everyday life of the neutralization reaction.
Answer:

• In neutralization reaction, an acid reacts with a base to form salt and water.
• In a neutralisation reaction the acid dissociates to form H⁺ ions and base dissociates to form OH ions.
• They combine to form H₂O molecules which mixes with the solvent.

Examples in daily life:

• When people suffer from acidity, they take some antacids to neutralise the acid in their stomach.
• If an ant stings us the pain is due to formic acid. It is neutralised by rubbing moist baking soda which is basic in nature.

c. Explain what is meant by electrolysis of water. Write the electrode reactions and explain them.
Answer:
Electrolysis of water:

• Electrolysis of water is the decomposition of water into oxygen and hydrogen gas due to an electric current being passed through acidified water.
• Cathode reaction:
  \(2 \mathrm{H}_{2} \mathrm{O}_{(l)}+2 \mathrm{e}^{-} \longrightarrow \mathrm{H}_{2(\mathrm{~g})}+2 \mathrm{OH}_{(\mathrm{aq}}\)
• Anode reaction:
  \(2 \mathrm{H}_{2} \mathrm{O}_{(l)} \longrightarrow \mathrm{O}_{2(\mathrm{~g})}+4 \mathrm{H}_{(\mathrm{aq})}^{+}+4 \mathrm{e}^{-}\)
• It is found that the volume of gas formed near the cathode is double that of the gas formed near the anode.
• Hydrogen gas is formed near the cathode and oxygen gas near the anode.
• From this, it is clear that electrolysis of water has taken place and its constituent element have been released.

9. Give a reason for the following.

a. Hydronium ions are always in the form H₃O⁺.
Answer:

• Acids in water gives H⁺ ions. These H⁺ ions do not exist freely in water.
• This is because H⁺ is a single proton, a hydrogen atom has only one proton and one electron.
• If the electron is removed to make H⁺, all that is left is an extremely tiny positively charged nucleus.
• This H ion will immediately combine with the surrounding water (H₂O) molecules to form (H₃O₄) hydronium ion.

b. Buttermilk spoils if kept in a copper or brass container.
Answer:

• Buttermilk contains an organic acid called as lactic acid.
• The lactic acid reacts with copper and brass and forms toxic compounds which are not fit for consumption.
• They are harmful and may cause food poisoning.
• So it is not advisable to keep buttermilk in brass or copper containers.

10. Write the chemical equations for the following activities.

(a) NaOH solution was added to HCl solution.
Answer:
When NaOH reacts with HCl, it gives NaCl and water.

(b) Zinc dust was added to dilute H₂SO₄.
Answer:
When zinc reacts with dilute sulphuric acid, it forms zinc sulphate and hydrogen gas is liberted.

(c) Dilute nitric acid was added to calcium oxide.
Answer:
When dilute nitric acid reacts with calcium oxide, it forms calcium nitrate and water.

(e) Carbon dioxide gas was passed through KOH solution.

(f) Dilute HCl was poured on baking soda.

11. State the differences.

a. Acids and bases
Answer:

Acids	Bases
(i) A substance which liberates H+ ions when dissolved in water is an acid (ii) Blue litmus turns red in an acid. (iii) The pH of an acid is less than 7. (iv) Acids are sour to taste (v) e.g. HCl, H2SO4	A substance which liberates OH– ions when dissolved in water is called a base. Red litmus turns blue in a base The pH of a base is greater than 7. Bases are bitter to taste, e.g. NaOH, KOH.

b. Cation and anion
Answer:

Cations	Anions
(i) Cations are ions with a net positive charge.	Anions are ions with a net negative charge.
(ii) Cations are generally formed by metals. When metals donate electrons, they have excess of protons, hence they form cations.	Anions are generally formed by non-metals. When non-metals accept electrons, they have excess of electrons, hence they form anions.
(iii) Cations are attracted towards the cathode which are negatively charged electrodes.	Anions are attracted towards the anode which are positively charged electrodes.
(iv) e.g.: Na+, Ca2+, Mg2+, K+ etc.	e.g.: O2 , S2-, Cl–, Br– etc.

c. the Negative electrode and the positive electrode.

Answer:

Negative Electrode	Positive Electrode
(i) Negatively charged electrodes are called as a cathode.	Positively charged electrodes are called as Anode.
(ii) Positively charged cations move towards the cathode or negative electrode.	Negatively charged anions move towards the anode or positive electrode.
(iii) Cathode accepts electrons from cations	Anode gives electrons to anions

12. Classify aqueous solutions of the following substances according to their pH into three groups : 7, more than 7, less than 7.

Common salt, sodium acetate, hydrochloric acid, carbon dioxide, potassium bromide, calcium hydroxide, ammonium chloride, vinegar, sodium carbonate, ammonia, sulphur dioxide.
Answer:

pH = 7	pH > 7	pH < 7
(a) common salt.	sodium acetate.	sulphur dioxide.
(b) potassium bromide.	sodium carbonate	hydrochloric acid.
(c)	ammonia.	carbon-dioxide.
(d)	calcium hydroxide.	ammonium chloride.
(e)		vinegar

Class 9 Science Chapter 5 Acids, Bases and Salts Intext Questions and Answers

Question 1.
How are the following substances classified into three groups with the help of litmus?
Lemon, tamarind, baking soda, buttermilk, vinegar, orange, milk, lime, tomato, milk of magnesia, water, alum.
Answer:

Basic Substance: Turns Red Litmus Blue	Acidic Substance: Turns Blue Litmus Red	Neutral Substance: No change in the colour of litmus
Baking Soda	Lemon	water
Lime	Tamarind
Milk of Magnesia	Buttermilk
	Vinegar
	Orange
	Milk
	Tomato
	Alum

Question 2.
Fill in the columns in the part of the following table:
Answer:

Question 3.
Complete the following table of the concentration of various aqueous solutions.
Answer:

Question 4.
Complete the following table of neutralization reactions and also write down the names of the acids, bases and salts in it.
Answer:

Question 5.
What are the names of the following compounds? NH₃, Na₂O, CaO.
Answer:
NH₃ : Ammonia
Na₂O : Sodium oxide
CaO : Calcium oxide

Question 6.
Into which type will you classify the above compounds, acid, base or salt?
Answer:
NH₃ : base
Na₂O : base
CaO : base

Question 7.
ive examples of monobasic, dibasic and tribasic acids.
Answer:
Monobasic acid examples: HNO₃, HCl, CH₃COOH
Dibasic acid examples: H₂SO₄, H₂CO₃
Tribasic acid examples: H₃BO₃, H₃PO₄

Question 8.
Give the three types of bases with their examples.
Answer:
Types of bases:
Monoacidic base examples : NaOH, KOH, NH₄OH
Diacidic base examples: Ca(OH)₂, Ba(OH)₂
Triacidic base examples: A(OH)₃, Fe(OH)₃

Question 9.
What are the colours of the following natural and synthetic indicators in acidic and basic solutions? Litmus, turmeric, jamun, methyl orange, phenolphthalein?
Answer:

Indicator	Colour in Acidic Solution	Colour in basic Solution
Litmus	Red	Blue
Turmeric	Yellow	Red
Jamun	Red	Blue-Green
Methyl orange	Red	Yellow
Phenolphthalein	Colourless	Pink

Question 10.
On mixing the substances as shown here, what are the resulting mixtures formed by mixing the following substances called?
(a) Water and salt
(b) Water and sugar
(c) Water and sand
(d) Water and sawdust
Answer:
(a) Water and salt – Homogeneous mixture
(b) Water and sugar – Homogeneous mixture
(c) Water and sand – Heterogeneous mixture
(d) Water and sawdust – Heterogeneous mixture

Question 11.
What would be the definition of an acid and a base with reference to the neutralization reaction?
Answer:

• Acid: An acid is a substance which neutralises a base to form salt and water.
• Base: A base is a substance which neutralises an acid to form salt and water.

Answer the following questions:

Question 1.
Take aqueous solution of sodium chloride, copper sulphate, glucose, urea, dil.H₂SO₄ and dil.NaOH in a beaker and test the electrical conductivity of the solutions. Answer the given below questions.

(a) With which solutions did the bulb glow?
Answer:
Solutions with which bulb glows: Aqueous solution of NaCl, CuSO₄, H₂SO₄ and NaOH.

(b) Which solutions are electrical conductors?
Answer:
Solutions which are electrical conductors:
NaCl, CuSO₄, H₂SO₄ and NaOH.

Question 2.
During electrolysis of copper sulphate, if electric current is passed through the electrolytic cell for a long time, what change would be seen at the anode?
Answer:

• When electricity is passed for a long time through copper sulphate solution, the following reaction is seen at the anode: Anode Reaction: Cu(s) → Cu²⁺(aq) + 2e^–
• All the copper atoms will get converted into copper ions and get deposited on the cathode. This process continues till the copper anode exists.

Question 3.
Would water be a good conductor of electricity?
Answer:
Pure water is not a good conductor of electricity.

Answer the following questions:

Question 1.
(i) With which solutions did the bulb glow?
(ii) Which solutions are electrical conductors?

Answer:
(i) The bulbs glows when the wire are immersed in NaCl solution.
(ii)

Solution	Results
1g Copper Sulphate Solution	Bulb glow
1g Glucose Solution	Bulb does not glow
1g Urea Solution	Bulb does not glow
5ml dil.H2SO4 Solution	Bulb glows
5ml dil. NaOH Solution	Bulb glows

Question 2.
What would be the definition of an acid and a base with reference to the neutralization reaction?
Answer:

• Acid: An acid is a substance which neutralises a base to form salt and water.
• Base: A base is a substance which neutralises an acid to form salt and water.

Question 3.
Dissolve 2g salt in 500ml pure water. Take 250 ml of this solution in a 500ml capacity beaker. Connect two electrical wires to the positive and negative terminals of a power supply. Remove the insulating cladding from about 2cm portions at the other ends of the wires. These are the two electrodes. Fill two test tubes upto the brim with the prepared dilute salt solution. Invert them on the electrodes without allowing any air to enter. Start the electric current under 6V potential difference from the power supply. Observe what happens in the test tubes after some time.
(a) Did you see the gas bubbles forming near the electrodes in the test tubes?
(b) Are these gases heavier or lighter than water?
(c) Are the volumes of the gases collected over the solution in the two test tubes the same or different?
(d) Test the solutions in the two test tubes with litmus paper, what do you see?
(e) Repeat the activity by using dilute H₂SO₄ as well as dilute NaOH as the electrolyte.
Answer:
(a) Yes, gas bubbles can be seen forming near the electrodes in the test tube.
(b) These gases are lighter than water.

(c) The volumes of gases collected over the solution in the two test tubes are different.
(d) The solution in the cathode turns red litmus blue while solution in anode turns blue litmus red.
(e) When the above experiment is repeated with dil H₂SO₄ and dil NaOH, Hydrogen gas is liberated at cathodes and oxygen gas is liberated at anode.

Answer the following questions:

Question 1.
Cut a lemon into two equal parts. Take the juice of each part into two separate beakers. Pour 10 ml of drinking water in one beaker and 20 ml in the second. Stir the solutions in both the beakers and taste them. Is there any difference in the tastes of the solutions in the two beakers? What is that difference?
Answer:

• In the above activity, the sour taste of the solutions is because of the solute, lemon juice in them.
• The quantity of the lemon juice is the same in both the solutions. Yet their tastes are different.
• The solution in the first beaker is more sour than the one in the second.
• Although the quantity of the solute is the same in both the solutions, the quantity of the solvent is different.
• Ratio of the quantity of the solute to the quantity of the resulting solution is different. This ratio is larger for the solution in the first beaker and therefore that solution tastes more sour.
• On the other hand, the proportion of the lemon juice in the total solution in the second beaker is smaller and taste is less sour.
• The taste of foodstuff depends upon the nature of the taste-giving ingredient and its proportions in the foodstuff.
• Similarly, all the properties of a solution depend on the nature of the solute and solvent and also on the proportion of the solute in a solution
• The proportions of a solute in a solution is called the concentration of the solute in the solution.

Question 2.
Take a big test tube. Choose a rubber stopper in which a gas tube can be fitted. Take a few pieces of magnesium ribbon in the test tube and add some dilute HCl to it. Take a lighted candle near the end of the gas tube and observe. What did you observe?

Answer:

• Magnesium metal reacts with dilute HCl and an inflammable gas, hydrogen, is formed.
• During this reaction, the reactive metal displaces hydrogen from the acid to release hydrogen gas.
• At the same time, the metal is converted into basic radical which combines with the acidic radical from the acid to form the salt.
  \(\mathrm{Mg}_{(\mathrm{s})}+2 \mathrm{HCl}_{(\mathrm{aq}) \longrightarrow} \underset{\rightarrow}{\mathrm{MgCl}_{2(\mathrm{aq})}}+\mathrm{H}_{2(\mathrm{~g})}\)

Question 3.
Take some water in a test tube and add a little red oxide (the primer used before painting iron articles) to it. Now add a small quantity of dilute HCl to it, shake the test tube and observe.
(a) Does the red oxide dissolve in water?
(b) What change takes place in the particles of red oxide on adding dilute HCl?
Answer:
(a) The chemical formula of red oxide is Fe₂O₃. It is insoluble in water.
(b) The water-insoluble red oxide reacts with HCl to produce a water-soluble salt FeCl₃.

• This gives a yellowish colour to the water.
• The following chemical equation can be written for this chemical change.
  \(\mathrm{Fe}_{2} \mathrm{O}_{3(\mathrm{~s})}+6 \mathrm{HCl}_{(\mathrm{aq})} \longrightarrow 2 \mathrm{FeCl}_{3(\mathrm{aq})}+3 \mathrm{H}_{2} \mathrm{O}_{(\mathrm{l})}\)

Question 4.
Fit a bent tube in a rubber cork. Take some lime water in a test tube and keep it handy. Take some baking soda in another test tube and add some lemon juice to it. Immediately fit the bent tube over it. Insert its other end into the lime water. Note down your observations of both the test tubes. Repeat the procedure using washing soda, vinegar and dilute HC1 properly. What do you see?
Answer:

• In this activity, when limewater comes in contact with the gas released in the form of an effervescence, it turns milky.
• This is a chemical test for carbon dioxide gas.
• When lime water turns milky, we infer that the effervescence is of CO₂.
• This gas is produced on the reaction of acids with carbonate and bicarbonate salts of metals.
• A precipitate of CaCO₃ is produced on its reaction with the lime water Ca(OH)₂.
• This reaction can be represented by the following chemical equation.
  \(\mathrm{Ca}(\mathrm{OH})_{2(\mathrm{aq})}+\mathrm{CO}_{2(\mathrm{~g})} \longrightarrow \mathrm{CaCO}_{3(\mathrm{~s})}+\mathrm{H}_{2} \mathrm{O}_{(\mathrm{l})}\)
• Washing soda is sodium carbonate Na2CO₃. It will react same as baking soda (NaHCO₃).
• Vinegar and HCl are acids, they do not react chemically with lemon juice.

Class 9 Science Chapter 5 Acids, Bases and Salts Additional Important Questions and Answers

Select the correct option

Question 1.
…………………. acid is present in lemon.
(a) malic acid
(b) tartaric acid
(c) citric acid
(d) butyric acid
Answer:
(c) Citric acid

Question 2.
Tamarind contains …………………. acid.
(a) Lactic acid
(b) tartaric acid
(c) matlic acid
(d) butyric acid
Answer:
(b) tartaric

Question 3.
Butter milk contains …………………. acid.
(a) butyric acid
(b) Lactic acid
(c) matlic acid
(d) citric acid
Answer:
(a) Butyricacid

Question 4.
If the basic radical is H+ the type of compound is ………………… .
(a) neutral
(b) base
(c) acid
(d) alkali
Answer:
(c) Acid

Question 5.
The name of compound NH3 is ………………… .
(a) nitric acid
(b) ammonium
(c) nitride
(d) ammonia
Answer:
(b) ammonia

Question 6.
The bases which are soluble in water are called as ………………… .
(a) indicators
(b) acids
(c) alkalis
(d) salts
Answer:
(c) alkalis

Question 7.
H₃PO₄ is a …………………. acid.
(a) monobasic
(b) tribasic
(c) tetrabasic
(d) dibasic
Answer:
(b) tribasic

Question 8.
According to pH scale pure water has a pH of ………………… .
(a) 6
(b) 7
(c) 5
(d) 8
Answer:
(b) 7

Question 9.
With reference to neutralization, metallic oxides are ………………… in nature.
(a) basic
(b) neutral
(c) acidic
(d) saline
Answer:
(a) basic

Question 10.
Molecular formula of blue vitriol is ………………… .
(a) CuSO₃ 5H₂O
(b) CuSO₄ 4H₂O
(c) CUSO₃ 4H₂O
(d) CUSO₄ 5H₂O
Answer:
(d) CUSO₄ 5H₂O

Question 11.
Molecular formula of crystalline alum is ………………… .
(a) KSO₄, AISO₄, 24H₂O
(b) K₂SO₄, ALSO₄, 24H₂O
(c) K₂SO₄, AL₂(SO₄)₃, 24H₂O
(d) KSO₄, Al₂(SO₄)₃, 24H₂O
Answer:
(c) K₂SO₄, AL₂(SO₄)₃, 24H₂O

Question 12.
Molecular formula for sodium oxide is ………………… .
(a) Na₂O
(b) NaO₂
(c) NaO
(d) Na₂O₂
Answer:
(a) Na₂O

Question 13.
H₂CO₃ is …………………. acid.
(a) monobasic
(b) dibasic
(c) tribasic
(d) tetrabasic
Answer:
(b) dibasic

Question 14.
Molecular formula of Red oxide is ………………… .
(a) Fe₂O₃
(b) CuO
(c) Fe₃O₄
(d) Na₂O
Answer:
(a) Fe₂O₃

Question 15.
The positive terminal electrode is called as ………………… .
(a) anode
(b) cathode
(c) anion
(d) cation
Answer:
(a) anode

Question 16.
…………………. produced in stomach helps in digestion.
(a) Hydrochloric acid
(b) Oxalic acid
(c) Sulphuric acid
(d) Nitric acid?
Answer:
(a) Hydrochloric acid

Question 17.
The solution turns blue litmus red, its pH is likely to be ………………… .
(a) 7
(b) 4
(c) 14
(d) 9
Answer:
(b) 4

Question 18.
An ionic compound NaCl is formed by ………………… .
(a) Na⁺ and Cl^–
(b) Na⁺ and Cl⁺
(c) Na^– and Cl^–
(d) Na^– and Cl⁺
Answer:
(a) Na⁺ and Cl^–

Question 19.
pH of strong acid is ………………… .
(a) 0
(b) 7
(c) 8
(d) 14
Answer:
(a) 0

Question 20.
HCl + NaOH → NaCl + H₂O is a …………………. reaction.
(a) neutralization
(b) crystallisation
(c) electrolysis
(d) dissociation
Answer:
(a) neutralization

Question 21.
Adding water to acid is an …………………. reaction.
(a) endothermic
(b) exothermic
(c) neutralisation
(d) crystallisation
Answer:
(b) exothermic

Find the odd one out:

(a) Rose Petal, Turmeric, Phenolphthalein, Indigo.
Answer:
Phenolphthalein is odd one out as rest are natural indicators while phenolphthalein is a synthetic indicator.

(b) Lime water, Vinegar, Acetic acid, Tartaric acid.
Answer:
Lime water is odd one out as this is basic in nature while rest are acidic.

(c) NaHCO₃, HCl, H₂SO₄, HNO₃
Answer:
NaHCO₃ is odd one out as it is base while rest are acids.

(d) Oxalic acid, Nitric acid, Citric acid, acetic acid.
Answer:
Nitric acid is odd one out as others are weak acids while Nitric acid is a strong acid.

(e) Crystalline, Liquid, Gases, Solid.
Answer:
Crystalline is odd one out as this is nature of a compound while others are physical states of compounds.

(f) Ca(OH)₂, Mg (OH)₂, NaOH, NH₄OH.
Answer:
NaOH is odd one out even though all are bases but NaOH is highly soluble in water compared to others.

Name the following:

Question 1.
Name the three types of ionic compounds.
Answer:
The three types of ionic compounds are acids, bases and salts.

Question 2.
Name the two constituents of molecule of an ionic compound.
Answer:

• Cation (positive ion/ basic radical)
• Anion (negative ion/acidic radical).

Question 3.
Name any three acids with their molecular formula.
Answer:

• Hydrochloric acid – HC1
• Sulphuric acid – H₂SO₄
• Nitric acid – HNO₃

Question 4.
Name any three bases with their molecular formula.
Answer:

• Sodium hydroxide – NaOH
• Potassium hydroxide – KOH
• Calcium hydroxide – Ca(OH)₂

Question 5.
Name any three salts with their molecular formula.
Answer:

• Sodium chloride – NaCl
• Potassium sulphate – K₂ SO₄
• Calcium chloride – CaCl₂

Question 6.
Name any two strong acids.
Answer:

• Hydrochloric acid – HC1
• Sulphuric acid – H₂ SO₄

Question 7.
Name any two weak acids.
Answer:

• Acetic acid – CH₃ COOH
• Carbonic acid – H₂ CO₃

Question 8.
Name any two strong bases.
Answer:

• Sodium hydroxide – NaOH
• Potassium hydroxide – KOH

Question 9.
Name a weak base.
Answer:
Ammonium hydroxide – NH₄OH

Question 10.
Name any two alkalis.
Answer:

• Sodium hydroxide – NaOH
• Potassium hydroxide – KOH

Question 11.
Name any two acids with their basicity 1 (monobasic)
Answer:

• Hydrochloric acid – HC1
• Nitric acid – HNO₃

Question 12.
Name any two acids with their basicity 2 (dibasic)
Answer:

• Sulphuric acid – H₂ SO₄
• Carbonic acid – H₂CO₃

Question 13.
Name any two acids with their basicity 3 (tribasic)
Answer:

• Boric acid – H₃BO₃
• Phosphoric acid – H₃PO₄

Question 14.
Name any two bases with their acidity 1 (monoacidic)
Answer:

• Sodium hydroxide – NaOH
• Potassium hydroxide – KOH

Question 15.
Name any two bases with their acidity 2 (diacidic)
Answer:

• Calcium hydroxide – Ca(OH)₂
• Barium hydroxide – Ba(OH)₂

Question 16.
Name any two bases with their acidity 3 (triacidic)
Answer:

• Aluminium hydroxide – Al(OH)₃
• Ferric hydroxide – Fe(OH)₃

Question 17.
Name the two units to express the concentration of the solution.
Answer:

• mass of solute in grams dissolved in one litre of the solution grams per litre, (g/L).
• Number of moles of the solute dissolved in one litre of the solution. Molarity (M) of the solution.

Match the columns:

Question 1.

Column ‘A’	Column ‘B’
(1) HNO3 (2) H3PO4 (3) CH3COOH (4) H2CO3	(a) Acetic acid (b) Carbonic acid (c) Phosphoric acid (d) Nitric acid

Answer:
(1-d),
(2- c),
(3 – a),
(4 – b)

Question 2.

Column ‘A’	Column ‘B’
(1) NH4OH (2) Ca(OH)2 (3) Al(OH)3 (4) Ba(OH)2	(a) Aluminium Hydroxide (b) Barium Hydroxide (c) Calcium Hydroxide (d) Ammonium Hydroxide

Answer:
(1-d),
(2- c),
(3 – a),
(4 – b)

Question 3.

Column ‘A’ Solution		Column ‘B’ pH
(1)	Milk	(a)	0
(2)	Milk of Magnesia	(b)	14
(3)	1 M HCl	(c)	10.5
(4)	1 M NaOH	(d)	6.5

Answer:
(1-d),
(2- c),
(3 – a),
(4 – b)

Question 4.

Column ‘A’	Column’B’
(1) Urine (2) Apples (3) Orange (4) Butter	(a) Butyric acid (b) Uric acid (c) Malic acid (d) Citric acid

Answer:
(1 – b),
(2 – c),
(3 – d),
(4 – a)

Question 5.

Column ‘A’	Column ‘B’
(1) Crystalline blue vitriol (2) Crystalline green vitriol (3) Crystalline (4) washing soda Crystalline alum	(a) FeS04-7H20 (b) K2S04-A12(S04)3.24H20 (c) CuS04-5H20 (d) Na2CO310H2O

Answer:
(1-c),
(2- a),
(3 – d),
(4 – b)

State whether the following statements are true or false and if false. Correct the false statement:

(1) The separation of H and CI in HCI is in absence of water.
(2) \(\mathrm{NaOH}_{(\mathrm{s})} \frac{\text { Water }}{\text { dissociation }}>\mathrm{Na}_{(\mathrm{aq})}^{+}+\mathrm{OH}_{(\mathrm{aq})}^{-}\)
(3) H₂SO₄ is a strong acid.
(4) NaC1 is an ionic compound.
(5) Turmeric is synthetic indicator.
(6) Metal + Dilute acid forms salt and water.
(7) Copper oxide is called red primer.
(8) Oxide of non-metal + Acid → Salt + Water.
(9) Zinc oxide reacts with sodium hydroxide to form sodium zincate.
(10) Al₂O₃ is an amphoteric oxide.
(11) Blue vitriol ZnSO₄. 7H₂O.
(12) Molecular formula for crystalline Ferrous sulphate is Fe5O₄. 5H₂O.
(13) NaCl in water does not conduct electricity.
(14) Phenolphthalein is colourless in base.
Answer:
(1) False. The separation of H⁺ and Cl^– in HC1 is in presence of water.
(2) True
(3) True
(4) True
(5) False. Turmeric is a natural indicator.
(6) False. Metal + Dilute acid forms salt and hydrogen gas.
(7) False. Iron oxide is called red primer.
(8) False. Oxide of izan-metal + Base → Salt + Wafer.
(9) True
(10) True
(11) False. Blue Vitriol is CuSO₄. 5H₂O.
(12) False. Molecular formula for crystalline Ferrous sulphate is FeSO₄. 7H₂O.
(13) False. NaCl in water conducts electricity.
(14) False, Phenolphthalein is colourless in acid and pink in base.

Define the following:

Question 1.
Acid
Answer:
An acid is a substance which on dissolving in water gives rise to H ion as the only cation. For example, HC1, H₂ SO₄, H₂CO₃.

Question 2.
Base
Answer:
A base is a substance which on dissolving in water gives rise to the OW ion as the only anion. For, NaOH, Ca(OH)₂

Question 3.
Strong Acid
Answer:
On dissolving in water, a strong acid dissociates almost completely, and the resulting aqueous solution contains mainly H ions and the concerned acidic radical. e.g. HC1, HBr, HNO₃, H₂SO₄.

Question 4.
Weak Acid
Answer:
On dissolving in water a weak acid does not dissociate completely, and the resulting aqueous solution contains H+ ion and the concerned acidic radical in small proportion along with large proportion of the undissociated molecules of the acid, e.g., H₂CO₃ (Carbonic acid), CH₃COOH (Acetic acid)

Question 5.
Strong Base
Answer:
On dissolving in water, a strong base dissociates almost completely and the resulting aqueous solution contains mainly OH ions and the concerned basic radicals, e.g. NaOH, KOH, Ca(OH)₂, Na₂O.

Question 6.
Weak Base
Answer:
On dissolving in water, a weak base does not dissociate completely and the resulting aqueous solution contains a small proportion of OH ions and the concerned basic radical along with a large proportion of undissociated molecules of the base. e.g. NH₄ OH.

Question 7.
Alkali
Answer:
The bases which are highly soluble in water are called alkali, e.g. NaOH, KOH, NH3. Here, NaOH and KOH are strong alkalis while NH₃ is a weak alkali.

Question 8.
Basicity of acids
Answer:
The number of H⁺ ions obtainable by the dissociation of one molecule of an acid is called its basicity.

Question 9.
Acidity of bases
Answer:
The number of OH ions obtainable by the dissociation of one molecule of a base is called its acidity.

Question 10.
Concentration of solute in the solution.
Answer:
The proportion of a solute in a solution is called the concentration of the solute in the solution.

Question 11.
Concentrated solution.
Answer:
When the concentration of a solute in its solution is high, it is a concentrated solution.

Question 12.
Dilute solution
Answer:
When the concentration of a solute in its solution is low, it is a dilute solution.

Question 13.
Neutralization
Answer:
A reaction in which an acid reacts with a base to form salt and water is called a neutalization reaction.
NaOH + HC1 → NaCl + H₂O
Base + Acid → Salt + Water

Question 14.
Cathode
Answer:
The electrode connected to the negative terminal of a battery by means of a conducting wire is called a cathode.

Question 15.
Anode
Answer:
The electrode connected to the positive terminal of a battery by means of a conducting wire is called an anode.

Question 16.
Cations
Answer:
Cations are positively charged ions which are attracted towards negative electrode (cathode) when electricity is passed into a solution of an ionic compound.

Question 17.
Anions
Answer:
Anions are negatively charged ions which are attracted towards the positive electrode (anode) when electricity is passed into a solution of an ionic compound.

Question 18.
Electrolytic cell
Answer:
An assembly that consists of a container with an electrolyte and the electrodes dipped in it, is called an electrolytic cell.

Question 19.
Molarity of a solution
Answer:
The number of moles of the solute dissolved in one litre of the solution is called the molarity of that solution. The molarity of a solute is indicated by writing its molecular formula inside a square bracket for example [NaCl] = 1

Question 20.
Acid – base indicators
Answer:
Some natural and synthetic dyes show two different colours in acidic and basic solution, and such dyes are acid base indicators.

Explain the following chemical reactions with the help of balanced equations:

Question 1.
Magnesium reacts with dilute hydrochloric acid.
Answer:
When magnesium reacts with dilute hydrochloric acid, it forms magnesium chloride and hydrogen gas is liberated.

Question 2.
When copper reacts with nitric acid.
Answer:
When copper reacts with nitric acid, it forms copper nitrate and hydrogen gas is liberated.

Question 3.
When ferric oxide reacts with diluted hydrochloric acid.
Answer:
When Ferric oxide reacts with diluted hydrochloric acid, it forms ferric chloride and water.

Question 4.
When calcium oxide reacts with dilute hydrochloric acid.
Answer:
When calcium oxide reacts with dilute hydrochloric acid, it forms calcium chloride and water.

Question 5.
When Magnesium oxide reacts with dilute hydrochloric acid.
Answer:
When magnesium oxide reacts with dilute hydrochloric acid, it forms magnesium chloride and water.

Question 6.
When zinc oxide reacts with dilute hydrochloric acid.
Answer:
When zinc oxide reacts with dilute hydrochloric acid, it forms zinc chloride and water.

Question 7.
When aluminium oxide reacts with hydrogen fluoride
Answer:
When aluminium oxide reacts with hydrogen fluoride, it forms Aluminium fluoride arid water.

Question 8.
When carbon dioxide reacts with sodium hydroxide.
Answer:
When carbon dioxide reacts with Sodium hydroxide, it forms Sodium carbonate and water.

Question 9.
When carbon dioxide reacts with potassium hydroxide.
Answer:
When carbon dioxide reacts with potassium hydroxide, it forms potassium carbonate and water.

Question 10.
When sulphur trioxide reacts with sodium hydroxide.
Answer:
When sulphur trioxide reacts with sodium hydroxide, it forms sodium sulphate and water.

Question 11.
When calcium hydroxide reacts with carbon dioxide.
Answer:
When calcium hydroxide reacts with carbon dioxide, it forms calcium carbonate and water.

Question 12.
When sodium carbonate reacts with hydrochloric acid.
Answer:
When sodium carbonate reacts with hydrochloric acid, it forms sodium chloride, carbon dioxide and water.

Question 13.
When sodium carbonate reacts with sulphuric acid.
Answer:
When sodium carbonate reacts with sulphuric acid, it forms sodium sulphate, carbon dioxide and water.

Question 14.
When calcium carbonate reacts with nitric acid.
Answer:
When calcium carbonate reacts with nitric acid, it forms calcium nitrate, carbon dioxide and water.

Question 15.
When potassium carbonate reacts with sulphuric acid.
Answer:
When potassium carbonate reacts with sulphuric acid, it forms potassium sulphate, carbon dioxide and water.

Question 16.
When sodium bicarbonate reacts with hydrochloric acid. OR Dilute HC1 was poured on baking soda
Answer:
When sodium bicarbonate reacts with hydrochloric acid, it forms sodium chloride, carbon dioxide and water.

Question 17.
When potassium bicarbonate reacts with nitric acid.
Answer:
When potassium bicarbonate reacts with nitric acid, it forms potassium nitrate, carbon dioxide and water.

Question 18.
When sodium bicarbonate reacts with acetic acid.
Answer:
When sodium bicarbonate reacts with acetic acid, it forms sodium acetate, carbon dioxide and water.

Question 19.
When copper sulphate is heated.
Answer:
When copper sulphate is heated it loses it’s water of crystallization to form white anhydrous copper sulphate.

Question 20.
When Ferrous sulphate is heated.
Answer:
When ferrous sulphate is heated it loses its water of crystallization to form white anhydrous ferrous sulphate.

Q.2. (B)-3. Complete the following table.

Question 1.
Complete the following table.
Answer:

Complete the following reactions.

Question 1.
Answer:

Question 2.
Metal + Dilute acid → Salt + Hydrogen
Answer:

Question 3.
Metal oxide + Dilute acid → SaIt + Water
Answer:

Question 4.
Oxide of non-metal + base → salt + water
Answer:

Question 5.
Carbonate salt of metal + dilute acid → Another salt of metal + Carbon dioxide + water
Answer:

Question 6.
Bicarbonate salt of metal + dilute acid → Another salt of metal + carbon dioxide + water
Answer:

Give scientific reasons:

Question 1.
Ionic compound NaCl has very high stability.
Answer:

• The outermost shell of both Na⁺ and Cl^– ions is a complete octet.
• An electronic configuration with a complete octet indicates a stable state.
• A molecule of NaCl has Na⁺ and Cl^– ions. An ionic bond is formed between these ions.
• The force of attraction between them is very strong as it is formed between the oppositely charged Na⁺ and Cl^– ions.
• Therefore NaCl, an ionic compound has very high stability.

Question 2.
Ionic compound dissociates while forming an aqueous solution.
Answer:

• On dissolving in water, an ionic compound forms an aqueous solution.
• In the solid state, the oppositely charged ions in the ionic compound are sitting side by side.
• When an ionic compound being to dissolve in water, the water molecules push themselves in between the ions of the compound and it separates them from each other, that is to say, an ionic compound dissociates while forming an aqueous solution.

Question 3.
Blue coloured copper sulphate crystals become colourless on heating.
Answer:

• Copper sulphate crystals are blue in colour and crystalline in form due to presence of water of crystallisation.
• Each molecule of crystalline copper sulphate contains five molecules of water of crystallisation (CuSO₄.5H₂O).
• On heating, the copper sulphate crystals lose the water of crystallisation and turns into white amorphous powder called as anhydrous copper sulphate.
• Therefore, blue coloured copper sulphate crystals become colourless on heating.

Question 4.
During electrolysis of water, a few drops of sulphuric acid are added to it.
Answer:

• Pure water is a covalent compound and hence it is a non-electrolyte and does not conduct electricity.
• When a few drops of sulphuric acid (H₂SO₄) are added to water.
• Being a strong acid it dissociates almost completely in its solution forming H⁺ cations and \(\mathrm{SO}_{4}^{2-}\) anions.
• The movement of these ions in the solution towards the respective electrodes amount to the conduction of electricity through the solution.
• Therefore, during electrolysis of water, a few drops of sulphuric acid are added to it.

Question 5.
Glucose is a non-electrolyte.
Answer:

• Glucose is a covalent compound
• It does not form any ions in its aqueous solution.
• Due to this aqueous solution of glucose does not conduct electronic current.
• Hence, glucose is a non-electrolyte.

Question 6.
Pure water is a poor conductor of electricity but aqueous solution of sodium chloride conducts electricity.
Answer:

• Pure water does not contain any free ions.
• Sodium chloride (NaCl) is an ionic compound made up of sodium cation (Na⁺) and chloride anion (Cl)
• When sodium chloride is dissolved in water , these ions dissociates in its aqueous solution. ‘
• These ions are free to move in the solution and conduct electricity.
• Therefore, pure water is a poor conductor of electricity but aqueous solution of sodium Chloride conducts electricity.

Question 7.
When carbon dioxide gas is passed through freshly prepared lime water, the limewater turns milky.
Answer:

• Limewater traditionally means a weak solution of the alkali calcium hydroxide Ca(OH)₂.
• When CO₂ is passed through limewater, it reacts with calcium hydroxide to form insoluble particulates (precipitate of calcium carbonate (CaCO₃).
• Calcium carbonate is weak basic salt and this gives a milky white precipitate.
  
• Hence, lime water turns milky when CO₂ gas is passed through it.

Q.3.1. Answer the following:

Question 1.
Write down chemical equations for
(a) Zinc oxide reacts with sodium hydroxide
(b) Aluminium oxide reacts with sodium hydroxide.
Answer:
(a) When zinc oxide reacts with sodium hydroxide, it forms sodium zincate and water

(b) When Aluminium oxide reacts with sodium hydroxide, it forms sodium aluminate and water.

Question 2.
Can we call Al₂O₃ and ZnO acidic oxides on the basis of above reactions.
Answer:

• No, because they also react with acids to form their respective salts and water.
• So, they show the properties of basic oxides also.

Question 3.
Define ‘amphoteric oxides’ and give two examples.
Answer:

• Amphoteric oxides are those oxides which react with both adds as well as bases to form their respective salts and water.
• Amphoteric oxides show the properties of both acidic oxides as well as basic oxides. ZnO and Al₂ O₃ are amphoteric oxides.?

Question 4.
Take a solution of 1g copper sulphate in 50ml water in a 100 ml capacity beaker. Use a thick plate of copper as anode and a carbon rod as cathode. Arrange the apparatus as shown in the figure and pass an electric current through the circuit for some time. Do you see any changes?
Answer:

• A thin film of copper metal is deposited on cathode which is immersed in solution. There is no change in colour of solution
• The electrons from cathode combines with Cu²⁺ ion from the solution forming Cu atoms which were then deposited on the cathode.

Q.3.5. Answer in brief:

Question 1.
What are acids, bases and salts?
Answer:

• Compounds having H⁺ as the basic radical in their molecules are called Acids.
• Compounds having OH^– as the acidic radical in their molecule are called Bases.
• Ionic compounds which have a basic radical other than H⁺ and an acidic radical other than OH^– are called salts.

Question 2.
What is an ionic bond?
Answer:

• The molecule of an ionic compound has two constituents namely cation (positive ion / basic radical) and anion (negative ion / acidic radical).
• There is a force of attraction between these ions as they are oppositely charged, and that is called the ionic bond.
• The force of attraction between one positive charge on a cation and one negative charge on an anion makes one ionic bond.

Question 3.
Give examples to show that proportions of H⁺ and OH^– ions in aqueous solution determines the properties of those solutions.
Answer:
The examples to show that proportions of H⁺ and OH^– ions in aqueous solution determines the properties of those solutions are :

• The proportions of H⁺ and OH ions divides soil into the acidic, neutral and basic, types of soil.
• It is necessary for blood, cell sap etc to have H⁺ and OH^– ions in certain definite proportions for their proper functioning.
• Fermentation carried out with the help of micro-organisms, other biochemical processes and also many chemical processes require the proportion of H⁺ and OH^– ions to be maintained within certain limits.

Question 4.
What is pH scale?
Answer:

1. In 1909, the Danish scientist Sorensen introduced a convenient new scale of expressing H⁺ ion concentration which is found to be useful in chemical and biochemical processes.
2. It is the pH scale (pH: power of hydrogen). The pH scale extends from 0 to 14. According to this scale pure water has a pH of 7. pH 7 indicates a neutral solution. This pH is the midpoint of the scale.
3. The pH of an acidic solution is less than 7 and?

Question 5.
Give the pH of following solutions.
Answer:

Question 6.
What is universal indicator? Which is the most accurate method of measuring the pH of a solution?
Answer:

• In the pH scale, the pH of solutions varies from 0 to 14 in accordance with the strength of the acid or base.
• To show these variations in pH, a universal indicator is used.
• A universal indicator shows different colours at different values of pH. A universal indicator is made by mixing several synthetic indicators in specific proportions.
• The pH of a solution can be determined by means of a universal indicator solution or the pH paper made from it.
• However, the most accurate method of measuring the pH of a solution is to use an electrical instrument called pH meter.
• In this method, pH is measured by dipping electrodes into the solution.

Answer in detail:

Question 1.
Explain the Arrhenius theory of acids and bases.
Answer:
The Swedish scientist Arrhenius put forth a theory of acids and bases in the year 1887. This theory gives definitions of acids and bases as follows:
Acid : An acid is a substance which on dissolving in water gives rise to H ion as the only cation. For example, HCl, H₂SO₄, H₂CO₃

Base: Abase is a substance which on dissolving in water gives rise to the OH ion as the only anion, For example, NaOH, Ca(OH)₂

Question 2.
Write a short note on Neutralization.
Answer:

• Take 10 ml of dilute HCl in a beaker, go on adding dilute NaOH drop by drop and record the pH.
• Stop adding the NaOH when the green colour appears on the pH paper, that is when the pH of solution becomes 7.
• Both HCl and NaOH dissociate in their aqueous solutions.
• Addition of NaOH to HCl solution is like adding a large concentration of OH ions to a large concentration of H⁺ ions.
• However water dissociates into H⁺ and OH ions to a very small extent.
• Therefore on mixing the excess OH^– ions combines with excess H⁺ ions and forms H₂O molecules which mix with solvent water.
• This change can be represented by the ionic equation shown as follows. H⁺ + Cl^– + Na⁺ + OH^– → Na⁺ + Cl^– + H₂O
• It can be observed that Na⁺ and CT ions are there on both the sides. Therefore the net ionic reaction is H⁺ + OH^– → H₂O
• As NaOH solution is added drop by drop to the HCl solution, the concentration of ff goes on decreasing due to combination with added OH ions, and that is how the pH goes on increasing.
• When enough NaOH is added to HCl, the resulting aqueous solution contains only Na⁺ and Cl^– ions, that is, NaCl, a salt, and the solvent water. The only source of H⁺ and OH^– ions in this solution is a dissociation of water.
• Therefore, this reaction is called the Neutralization reaction. The Neutralization reaction is also represented by the following simple equation.
  

Question 3.
Explain the water of Crystallization.
Answer:

• Take some crystals of blue vitriol (CuSO₄. 5H₂O) in a test tube. Heat the test tube on a low flame of a burner.
• It was observed that on heating, the crystalline structure of blue vitriol broke down to form a colourless powder and water came out.
• This water was part of the crystal structure of blue vitriol. It is called water of crystallization.
• On adding water to the white powder a solution
  
  was formed which had the same colour as the solution in the first test tube.
• From this we come to know that no chemical change has occurred in the crystals of blue vitriol due to heating.
• Losing water on heating blue vitriol, breaking down of the crystal structure, losing blue colour and regaining blue colour on adding water are all physical changes.
  
• Similarly, ferrous Sulphate crystals also contain 7 molecules of water of crystallization which are lost on heating.
• The reaction is represented as
  
• Ionic compounds are crystalline in nature. These crystals are formed as a result of definite arrangement of ions.
• In the crystals of some compounds, water molecules are also included in this arrangement.
• That is the water of crystallization. The water of crystallization is present in a definite proportion of the chemical formula of the compound.

Question 4.
Explain the conduction of electricity through solutions of ionic compounds
Answer:

1. Electrons conduct electricity through electrical wires, and ions conduct electricity through a liquid or a solution.
2. Electrons leave the battery at the negative terminal, complete the electric circuit and enter the battery at the positive terminal.
3. When there is a liquid or a solution in the circuit, two rods, wires or plates are immersed in it. These are called electrodes.
4. Electrodes are made of conducting solid. The electrode connected to negative terminal of a battery by means of a conducting wire is called a cathode and the electrode connected to the positive terminal of a battery is called anode.
5. We have seen that salts, strong acids and strong bases dissociates almost completely in their aqueous solutions.
6. Therefore the aqueous solutions of all these three contain large number of cations and anions.
7. A characteristic of liquid state is the mobility of its particles. Due to its mobility the positive charged ions of the solution are attracted to the negative electrode or cathode.
8. On the other hand, the negative charged ions of the solution are attracted to the positive electrode or anode.
9. The movement of ions in the solution towards the respective electrodes accounts to the conduction of electricity through the solution.
10. From this we can understand that those liquids or solutions which contain a large number of dissociated ions conduct electricity.
    

 

Balbharti Maharashtra State Board Class 9 Science Solutions Chapter 14 Substances in Common Use Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 9 Science Solutions Chapter 14 Substances in Common Use

Class 9 Science Chapter 14 Substances in Common Use Textbook Questions and Answers

1. Fill in the blanks.

a. The number of molecules of water of crystallization in washing soda is …………….…. .
b. The chemical name of baking soda is …………….…. .
c. …………….…. is used in treatment of hyperthyroidism.
d. The chemical name of Teflon is …………….…. .
Answer:
a. 10
b. Sodium bicarbonate
c. Iodine -123
d. Polytetra fluoroethylene (C₂F₄)_n

2. Match the pairs

Group A	Group B
1. Saturated brine	a. sodium metal freed
2. Fused salt	b. basic salt
3. CaOCl2	c. crystallization of salt
4. NaHCO3	d. oxidation of colour

Answer:
(1 – c),
(2 – a),
(3 – d),
(4 – b)

3. Write answers to the following

a. What is meant by radioactivity?
Answer:

• Elements with a high atomic number such as uranium, thorium, radium have a property of spontaneously emitting invisible, highly penetrating and high energy radiation.
• This property is called radioactivity.
• A substance having this property is called a radioactive substance.

b. When is said to be the nucleus unstable?
Answer:

• It is the balance of protons and neutrons in a nucleus which determines whether a nucleus will be stable or unstable.
• Too many neutrons or protons upset this balance disrupting the binding energy from the strong nuclear forces making the nucleus unstable.

c. Which diseases are caused by artificial food colours?
Answer:
Diseases like ADHD (Attention Deficit Hyperactivity Disorder) can affect children due to excessive consumption of foods with added food colours.

d. Where in the industrial field is radioactivity used?
Answer:
Industrial field Radiography

• Internal cracks and voids in cast iron articles and iron solder can be detected with the help of gamma rays.
• For this purpose, isotopes like cobalt-60, iridium-192 are used in the radiography camera.
• This technique is used for detecting flaws in metal work.

Measurement of thickness, density and level

• It is necessary to maintain the required thickness in the manufacture of aluminium, plastic, iron sheets of differing thickness.
• In the manufacturing process, a radioactive substance is placed on one side and an instrument to measure radiation on the other.
• The radiation read by the measuring instrument varies with the thickness of the sheet.
• Material inside a packing can also be examined by the same technique.

Luminescent paint and radio luminescence:

• The radioactive substances radium, promethium, tritium with some phosphor are used to make certain objects visible in the dark, for example, the hands of a clock, and certain other objects.
• Krypton-85 is used in HID (High-Intensity Discharge) lamps while promethium – 147 is used in portable X-ray units as the source of beta rays.

Use in Ceramic articles:

• Luminous colours are used to decorate ceramic tiles, utensils, plates, etc.
• Earlier uranium oxide was used in these paints.

e. Write down properties of teflon.
Answer:
Properties of teflon :

• The atmosphere and chemical substances have no effect on Teflon.
• Neither water nor oil will stick to Teflon coated articles.
• High temperatures do not affect Teflon as its melting point is 327 °C.
• Teflon coated articles are easy to clean.

f. What type of colours will you use to celebrate ecofriendly Rang Panchami? Why?
Answer:

• We regularly use artificial colours on Rang Panchami.
• The red colour used on Rang Panchami is very dangerous. It contains a high proportion of mercury in it.
• This poses risks like blindness, skin cancer, asthma, itching of the skin, permanent blocking of sweat pores, etc.
• Therefore, it is necessary to use eco-friendly colours.
• We will prepare colours for Rang Panchami from natural resources such as beet root, flowers of flame of forest, spinach, flame tree (gulmohar) and protect your health by using these.

g. Why has the use of methods like Teflon coating become more common?
Answer:
The use of methods like Teflon coating became more common because of following properties of teflon:

• The atmosphere, rain water and chemical substances have no effect on Teflon.
• Neither water nor oil will stick to Teflon coated articles.
• High temperatures do not affect Teflon as its melting point is 327 °C.
• Teflon coated articles are easy to clean.
• Teflon is a poor conductor of electricity.

4. Give a scientific explanation

a. Bleaching powder has the odour of chlorine.
Answer:

• Bleaching powder undergoes slow decomposition due to the carbon dioxide in air and chlorine gas is released.
• Bleaching powder gets its property because of this release of chorine gas.
  

b. The hard water of a well becomes soft on adding washing soda to it.
Answer:

• The hard water from a well or a bore-well becomes soft on adding washing soda and we come to know this from the lather formed on it.
• The hardness of water is due to the presence of chlorides and sulphates of calcium and magnesium in it.
• Na₂CO₃ is added to it to soften such water and make it suitable for use.
• The reaction with Na₂CO₃ causes the formation of insoluble carbonate salts of magnesium and calcium.
  MgCl_2(aq) + Na₂CO_3(s) → MgCO_3(s) + 2 NaCl_(s)

c. Soap forms a precipitate in hard water.
Answer:

• When soap is mixed with hard water, calcium and magnesium salts of fatty acids are formed.
• These being water insoluble, they form a precipitate and that is why lather is not formed.

d. The particles of powder are given an electric charge while spraying them to form the powder coating.
Answer:

• Powder coating is a method of applying a layer harder than paint on the surface of an iron object to prevent rusting.
• In this method, a polymer resin, a pigment and some other ingredients are melt, mixed, cooled and ground into a uniform powder.
• This powder is sprayed on the polished metal surface by electrostatic spray deposition (ESD).
• In this method, the particles of the powder are given an electrostatic charge due to which a uniform layer of the powder sticks to the metal surface.
• Then the object is heated in the oven along with the coating.
• A chemical reaction occurs in the layer, resulting in the formation of long cross-linked polymeric chains.

e. The aluminium article is used as an anode in the anodising process.
Answer:

• A protective layer is formed naturally on the surface of aluminium metal by reaction with oxygen in air.
• In the anodizing process, this layer is made of the desired thickness. Anodizing is done by electrolysis.
• Dilute Sulphuric acid is taken in the electrolytic cell and the aluminium article is dipped in it as the anode.
• When an electric current is passed, hydrogen gas is released at the cathode and oxygen gas at the anode.
• A reaction with oxygen occurs and a layer of hydrated aluminium oxide is formed on the anode. Therefore, aluminium article is used as an anode in the anodizing process.

f. When the radiation coming out from certain radioactive substance is passed through an electric field, marks are found at three places on the photographic plate placed in its path.
Answer:
(i) When the radiation coming out from certain radioactive substance is passed through an electric field, marks are found at three places on the photographic plate placed in its path. This is because the radiation coming out from radioactive substance are of three types Alpha rays, Beta rays and Gamma rays.

(ii) The rays which get deviated slightly towards negatively charged plate are called alpha rays. They get deviated towards negatively charged plate because they are made of positively charged particles, called as alpha particles (He++).

(iii) The rays which get deviated substantially towards the positively charged plate are called beta rays. They get deviated towards a positively charged plate because they are made of negatively charged particles called as beta particles (e-).

(iv) The rays which do not deviate at all are called gamma rays. They are uncharged electromagnetic radiation. Hence, marks are found at three places on the photographic plate. (For diagram refer Fig. 14 .2 from Q. 4(3))

g. A certain type of ceramic tiles are fixed on the outer layer of a space shuttle.
Answer:
(i) Each shuttle is covered by more than 24,000 of the six- by six-inch advance ceramic tiles. This tiles withstand high temperatures without decomposing. They are brittle, water-resistant and electrical insulator. Most of the tiles are made of silica fibres, which are produced from high-grade sand (SiO₂).

(ii) Silica is an excellent insulator because it transports heat slowly. When the outer portion of a tile gets hot, the heat takes a long time to work its way down through the rest of the tile to the shuttle’s skin. The tiles keep the orbiter’s aluminium skin at 350 degrees or less.

(iii) The silica fibers are mixed with water and chemicals, and the mixture is poured into molds, which are zapped in microwave ovens at 2,350°C to fuse the silica fibres. Tiles are too brittle to attach to the orbiter directly.

(iv) The shuttle’s skin contracts slightly while in orbit, then expands during re-entry.

(v) In addition, the stresses of launch and re-entry cause the skin to flex and bend. Such motions could easily crack the tiles or shake them off. To keep them in place, workers glue the tiles to flexible felt-like pads, then glue the pads to the orbiter.

5. Write answers to the following

a. Write about artificial food colours, the substances used in them and their harmful effects.
Answer:
(a) Artificial food colour and substances in them.

• Food colours are mixed in most soft drinks and foodstuffs available in the market.
• These food colours are in the form of powders, gels and pastes.
• Food colours are used in domestic as well as commercial products.
• Certain colours and essences are added to ice cream, ice candies, sauce, fruit juices, cold drinks, pickles, jams and jelly.
• Food colours are often found to be added to packaged meat (chicken, mutton), chilli powder, turmeric, sweets and other similar substances so as to give them a good colour.
• Tetrazene, sunset yellow are artificial food colours used extensively.

(b) Harmful effects of artificial food colours

1. Food colours added to pickles, jam and sauce contain small quantities of lead and mercury. These can be harmful for those who consume these products on a regular basis.
2. Diseases like ADHD (Attention Deficit Hyperactivity Disorder) can affect children due to excessive consumption of foods with added food colours.

b. What is meant by water of crystallization? Give examples of salts with water of crystallization, and their uses.
Answer:
The exact number of water molecules which are chemically bonded to a molecule of a salt within a hydrated crystalline compound is called as water of crystallization are:

Some substances in our daily use which contain water of crystallization are:

• Alum (Potash alum – K₂SO₄.Al₂(SO₄)₃.24H₂O)
• Borax (Na₂B₄O₇.10H₂O)
• Epsom salt (Magnesium sulphate MgSO₄.7H₂O)
• Barium chloride (BaCl₂.2H₂O)
• Sodium sulphate (Glauber’s salt Na₂SO₄.10 H₂O)
• Blue vitriol (Copper Sulphate – CuSO₄.5H₂O)

Uses of these salts are as given below:
(i) Alum (Potash alum – K₂SO₄.Al₂(SO₄)₃.24H₂O)

• Alum is used in the process of water purification.
• Because of the property of coagulation, the solid impurities in water come together, become heavy and settle to the bottom. As a result, the impure water or muddy above becomes clear.
• Alum powder, found in the spice section of many grocery stores, may be used in pickling recipes as a preservative to maintain fruit and vegetable crispness.
• Alum is used as the acidic component of some commercial baking powders.
• Alum has been used as an after shave treatment.

(ii) Borax (Na₂B₄O₇.10H₂O)

• Borax today is used for many cleaning purposes.
• It is used to make homemade laundry detergent.
• It is added as a cleaning boost to any other detergent.
• It even keeps ants and other pests away.

(iii) Epsom salt (Magnesium sulphate MgSO₄.7H₂O)

• Epsom salt is used as a relaxing magnesium bath soak.
• To grow better vegetables – Add a tablespoon of Epsom salt to the soil below a vegetable plant to boost growth.

(iv) Barium chloride (BaCl₂.2H₂O)

• In industry, Barium chloride is mainly used in the purification of brine solution in caustic chlorine plants.
• It is also used in the manufacture of heat treatment salts.
• It is used in hardening of steel.
• It is used in the manufacture of pigments.

(v) Sodium sulphate (Glauber’s salt Na₂SO₄.10H₂O)

• In the laboratory, anhydrous Sodium sulphate is widely used as an inert drying agent, for removing traces of water from organic solutions.
• Glauber’s salt, the decahydrate, is used as a laxative.

(vi) Blue vitriol (Copper sulphate CuSO₄.5H₂O)

• Blue vitriol is used in the blood test for diagnosing anaemia.
• Slaked Time is used with blue vitriol in the Bordeaux mixture which is used as a fungicide on fruits like grapes and musk melon.

c. Write briefly about the three methods of electrolysis of sodium chloride.
Answer:

• When an electric current is passed through a saturated solution of sodium chloride (brine) it is electrolysed and hydrogen gas is released at the cathode while chlorine gas is released at the anode.
• This method is used for production of chlorine gas. In this method an important basic compound NaOH is formed in the cell.
• Chemical reaction
  2NaCl + 2H₂O → 2NaOH + Cl₂ ↑ + H₂↑
• When salt is heated to a high temperature (about 800 °C), it melts. This is called the fused state of the salt.

6. Write the uses.

a. Anodizing
b. Powder coating
c. Radioactive substances
d. Ceramic
Answer:
(a) Anodizing : Anodizing is done on aluminum cooking utensils like griddles and cookers.

(b) Powder coating : Powder coating is done on iron objects to prevent rusting. Also, on Plastic and Medium density fibre (MDF) board, to make them highly durable, hard and attractive.

(c) Radioactive substances:
(I) Industrial field:
(i) Industrial Radiography : Internal cracks and voids in cast iron articles and iron solder can be. detected with the help of gamma rays. For this purpose, isotopes like cobalt-60, iridium-192 are used in the radiography camera. This technique is used for detecting flaws in metal work.

(ii) Measurement of thickness, density and level: It is necessary to maintain the required thickness in the manufacture of aluminium, plastic, iron sheets of differing thickness. In the manufacturing process, a radioactive substance is placed on one side and an instrument to measure radiation on the other. The radiation read by the measuring instrument varies with the thickness of the sheet. Material inside a packing can also be examined by the same technique.

(iii) Luminescent paint and radioluminescence:
The radioactive substances radium, promethium, tritium with some phosphor are used to make certain objects visible in the dark, for example, the hands of a clock, and certain other objects. Krypton-85 is used in HID (High Intensity Discharge) lamps while promethium-147 is used in portable X-ray units as the source of beta rays.

Use in Ceramic articles – Luminous colours are used to decorate ceramic tiles, utensils, plates, etc. Earlier uranium oxide was used in these paints.

(II) Field of agriculture :

• The genes and chromosomes that give seeds properties like fast growth, higher productivity, etc. can be modified by means of radiation.
• The radioactive isotope cobalt-60 is used for food preservation.
• Onions, potatoes are irradiated with gamma rays from cobalt-60 to prevent their sprouting.
• Strontium-90 is used as a tracer in the research on various crops.

(III) Medical science:

• Polycythemia : The red blood cell count increases in the disease polycythemia. Phosphorus- 32 is used in its treatment.
• Bone cancer : Strontium-89, strontium-90, samarium-153 and radium-223 are used in the treatment of bone cancer.
• Hyperthyroidism : Enlargement of thyroid gland, weight loss in spite of appetite, insomnia are the symptoms of hyperthyroidism.
• It occurs due to overproduction of hormones by the thyroid gland. Iodine-123 is used in the treatment of hyperthyroidism.
• Tumour detection : Boron-10, iodine-131, cobalt-60 are used in treatment of brain tumour, while arsenic-74 is used in detection of small tumours in the body.

(d) Ceramic : Pots made by a potter, Mangalore roofing tiles, construction bricks, pottery, terracotta articles are some examples of common ceramic articles that we see around.

7. Write the harmful effects

a. Artificial dye
b. Artificial food colour
c. Radioactive substances
d. Deodorant
Answer:
(a) Artificial dye:

• Dyeing hair can have adverse effects like hair fall, damage to hair texture, burning of skin, adverse effect on eyes, etc.
• Lipstick contains a dye named carmine. It does not affect lips but causes stomach disorders.
• Excessive use of plants for making natural dyes results in deterioration of the environment.

(b) Artificial food colour:

• Food colours added to pickles, jams and sauces contain small quantities of lead and mercury. These can be harmful for those who consume these products on a regular basis.
• Diseases like ADHD (Attention Deficit Hyperactivity Disorder) can affect children due to excessive consumption of foods with added food colours.

(c) Radioactive substances :

• The central nervous system is affected by radioactive radiations.
• Hereditary defects are generated by bombardment of radiation on D.N.A in the body.
• Radioactive radiation can penetrate the skin, and causes diseases like skin cancer, leukemia.
• The radioactive pollutants created due to explosions enter the body through air and it is difficult to control them.
• The radioactive pollutants released in the sea enter the bodies of fishes and through them enter the human body.
• The radioactive paint on the watch can cause cancer.
• The radioactive isotopes strontium-90 can enter the body through plants, fruits, flowers, cereals, milk, etc. and cause diseases like bone cancer, leukemia.

(d) Deodorant:

• Aluminium – Zirconium compounds are the most harmful chemicals in the deodorant. Disorders like headache, asthma, respiratory disorders, heart disease are likely to occur without our knowledge.
• There is a possibility of various skin disorders and also skin cancer due to the aluminium chlorohydrates.

8. Write the chemical formula Bleaching powder, common salt, baking soda, washing soda
Answer:

Common name	Chemical name
Bleaching powder	CaOCl2
Common salt	NaCl
Baking soda	NaHCOs
Washing soda	Na2CO3.10 H2O

9. Explain what you see in the following picture

Powder coating
Answer:

1. This picture shows powder coating of the given object. Powder coating is a method of applying a layer harder than paint on the surface of an iron object to prevent rusting.
2. In this method, a polymer resin, a pigment and some other ingredients are melt mixed, cooled and ground into a uniform powder.
3. This powder is sprayed on the polished metal surface by electrostatic spray deposition (ESD).
4. In this method, the particles of the powder are given an electrostatic charge due to which a uniform layer of the powder sticks to the metal surface.
5. Then the object is heated in the oven along with the coating.
6. A chemical reaction occurs in the layer, resulting in the formation of long cross-linked polymeric chains.
7. This powder coating is highly durable, hard and attractive. Powder coating can be done on plastic and medium density fibre (MDF) board in day to day use as well.

Class 9 Science Chapter 14 Substances in Common Use Intext Questions and Answers

Can you recall?

Question 1.
What are detergents?
Answer:

• Detergent is a water-soluble cleansing agent which combines with impurities and dirt to make them more soluble, and differs from soap in not forming a scum with the salts in hard water.
• Today, detergents are more likely to be a mixture of synthetic chemicals and additives cooked up in a huge chemical plant and, unlike traditional soap, they’re generally liquids rather than solids.
• Detergents are used in everything from hair shampoo and clothes, washing powder to shaving foam and stain removers.
• The most important ingredients in detergents are chemicals called surfactants – a word made from bits of the words surface-active agents.

Question 2.
What are the important substances that we use in day to day life? For what purposes do we use them?
Answer:
Some of the substances we use in our day to day life and the purpose of using them are as follows:

Toothpaste: for cleaning teeth and maintaining hygienic conditions of mouth.

Soap : for bathing and maintaining hygienic conditions of body.

Natural and artificial fibers : we wear them as clothes to protect our body and many other purposes.

Washing powder: for cleaning clothes. Vegetables, fruits and food grains : they provide us with necessary vitamins, minerals and carbohydrates required for proper functioning of body.

Water : very important for our survival and many other functions of day to day life.

Metals : for making buildings, bridges, roads, vehicles, trains, ships, airplanes, utensils etc.

Acids, bases and salts : used for various purposes, for example, Sodium chloride which is used as common salt, a very necessary ingredient of our daily food without which our food is tasteless.

Question 3.
How are the various substances in day to day use classified from the scientific point of view?
Answer:
The various substances in day to day use are classified from the scientific point of view as elements, compounds, mixtures, metals, non-metals, acids, bases and salts.

Question 4.
Which chemicals and apparatus will you use in the laboratory for making soap?
Answer:
For making soap in laboratory following chemicals and apparatus are used :
Chemicals : Vegetable oil (coconut oil, castor oil, soya bean oil etc.)
Sodium hydroxide (NaOH)
Salt (Sodium chloride NaCl)

Apparatus :
500 ml glass beaker
Burner
Flat glass tray
Knife

Soaps are essential to personal and public health. They safely remove germs, soils and other contaminants and help us to stay healthy and make our surroundings more pleasant. Soaps are made from fats and oils or their fatty acids.

Take about 20 ml of any vegetable oil (coconut oil, castor oil, soybean oil etc.) in a beaker. Put about 30 – 35 ml of NaOH in it and heat and stir the mixture till a paste is formed. Now add a little salt. Stir again and allow the mixture to cool in a flat glass tray, on cooling it solidifies. Take a knife and cut it in soap bars as per the size required.

Question 5.
What are salts?
Answer:

• Inorganic substances occur naturally in the form of salts rather than acids or bases.
• The ionic compounds which do not contain H+ and OH ions and contain only one kind of cation and anion are called simple salts.
• For example, Na₂SO₄, K₃PO₄, CaCl₂.
• The sea is said to be a rich source of salts. In fact, the sea is a rich source of several salts of various elements such as chlorine, sodium, magnesium, potassium, calcium, bromine.
• The important salts found in sea water are sodium chloride, magnesium chloride, magnesium sulphate, potassium chloride, calcium carbonate and magnesium bromide.

Answer the following questions:

Question 1.
How is it determined whether a substance is acidic, basic or neutral?
Answer:

• In the pH scale, the pH of solutions varies from 0 to 14 in accordance with the strength of the acids or base.
• The pH scale shows different colours at different values of pH. Colour from dark red to yellow or from pH value 0 to 6 indicates the substances are acidic.
• Colour from light blue to violet or from pH value 8 to 14 indicates the substances are basic.
• Green colour or pH value 7 indicates the substances are neutral.

Question 2.
A sweets shop looks attractive because of the colourful sweets displayed there. Which colours are used in these substances?
Answer:

• Food colours and essences are used in sweets to make them colourful and tasty.
• These food colour are in the form of powders, gels and pastes.
• Food colours are natural as well as artificial.
• The food colours prepared from seeds, beetroot, flowers and fruit concentrate are natural.
• Tetrazene, sunset yellow are artificial food colours used extensively.

Question 3.
Make a list of substances in day to day use in accordance with their pH value (O to 14).
Answer:

Question 4.
A doctor gives you medicines when you fall ill. What are the medicines made from?
Answer:

• Long before pure chemicals were manufactured in labs, people used plants for medicine.
• There are over a hundred active ingredients derived from plants for use as drugs and medicines.
• The emergence of synthetic chemistry in the 1800s opened up new avenues for scientific research into drugs.
• Many chemists tried to locate medically active ingredients in plants (for instance the important malaria remedy quinine), and subsequently tried to make those substances in the laboratory in order to become independent of plant supplies.
• At the same time, a new industry developed as scientists developed processes to synthesise new chemicals on a large scale.
• New production methods developed in the late 1800s and early 1900s made it easier to standardise, package and transport medicines.

Question 5.
What problems do you get after playing colours on Rang Panchami? Why?
Answer:

• After playing colours on Rang Panchami we may get problems such as risks of blindness, skin cancer, asthma, itching of the skin, permanent blocking of sweat pores etc.
• This is because the colours used in rang panchami specially the red colour is very dangerous.
• It contains a high proportion of mercury in it.

Question 6.
Which colours will you use to prevent the occurrence of these problems?
Answer:

• To prevent the occurrence of these problem, instead of using artificial colours, natural colours should be used.
• Natural colours are prepared from natural resouroes such as beet root, flowers of flame of forest, spinach, flame tree (gulmohar).

Question 7.
What problem do you have on painting the house and furniture?
Answer:

• On painting the house and furniture with artificial colours which are dangerous, we may get problems such as risks of blindness, skin cancer, asthma, itching of the skin, permanent blocking of sweat pores, etc.
• This is because the colours contain a high proportion of mercury in it.

Question 8.
What is the property of Teflon because of which it is used in non-stickware?
Answer:
Following are the properties of teflon because of which it is used in nonstick cookware.

• The atmosphere and chemical substances have no effect on Teflon.
• Neither water nor oil will stick to Teflon coated non-stickware.
• High temperatures do not affect Teflon as its melting point is 327 °C.
• Teflon coated non-stickware are easy to clean.

Answer the following questions:

Question 1.
What is the strip shown below? What is it used for?
Answer:
The strip shown is pH metre scale. It is used to determined pH of solutions.

Question 2.
Prepare saturated solutions of given salts and put 2-3 drops of the universal indicator in them and note your observations in the table below:
Answer:

Class 9 Science Chapter 14 Substances in Common Use Additional Important Questions and Answers

Select the correct option:

Question 1.
Baking soda is ………………………… .
(a) non-metallic
(b) metallic
(c) acidic
(d) basic
Answer:
(d) basic

Question 2.
During electrolysis of NaCl in the fused state ………………………… is formed at cathode.
(a) sodium
(b) oxygen
(c) oxalic acid
(d) butyric acid
Answer:
(a) sodium

Question 3.
………………………… is known as chloride of lime.
(a) Calcium carbonate
(b) Sodium bicarbonate
(c) Sodium chloride
(d) Bleaching powder
Answer:
(d) Bleaching powder

Question 4.
Salt obtained from certain type of rock is called ………………………… .
(a) hard salt
(b) rock salt
(c) stone salt
(d) pure salt
Answer:
(b) rock salt

Question 5.
The ………………………… % aqueous solution of salt is called brine.
(a) 25
(b) 60
(c) 30
(d) 50
Answer:
(a) 25

Question 6.
The molecular formula for baking soda is ………………………… .
(a) Na₂CO₃
(b) NaHCO₃
(c) Na₂SO₄
(d) NaNO₃
Answer:
(b) NaHCO₃

Question 7.
Bleaching powder is also called ………………………… .
(a) Calcium oxygen chlorine
(b) Calcium oxychloride
(c) Calcium hydroxide
(d) Calcium oxalate
Answer:
(b) Calcium oxychloride

Question 8.
NaHCO₃ is also called as ………………………… .
(a) Sodium carbonate
(b) Sodium bicarbonate
(c) Sodium carbon oxide
(d) Sodium chloride
Answer:
(b) sodium bicarbonate

Question 9.
Molecular formula for Magnesium bromide is ………………………… .
(a) MgBr
(b) Mg₂Br
(c) Mg₂Br₂
(d) MgBr₂
Answer:
(d) MgBr₂

Question 10.
The molten state of NaCl is also called as ………………………… .
(a) solid state
(b) semi-solid
(c) gaseous state
(d) fused state
Answer:
(d) fused state

Question 11.
Substance used to make hard water soft is ………………………… .
(a) Na₂CO₃.10H₂O
(b) Na₂CO₃.H₂O
(c) NaCO₃.10H₂O
(d) NaCO₃.H₂O
Answer:
(a) Na₂CO₃.10H₂O

Question 12.
The fixed number of molecules of water in alum is ………………………… .
(a) 24
(b) 10
(c) 7
(d) 2
Answer:
(a) 24

Question 13.
Chlorine gas is a strong ………………………… agent.
(a) reducing
(b) oxidising
(c) neutral
(d) acidic
Answer:
(b) oxidising

Question 14.
Bleaching powder is ………………………… in colour.
(a) brownish red
(b) yellowish-white
(c) pinkish brown
(d) greenish blue
Answer:
(b) yellowish-white

Question 15.
Soap is ………………………… in nature.
(a) acidic
(b) basic
(c) neutral
(d) fuming
Answer:
(b) basic

Question 16.
Melting point of NaCl is ………………………… .
(a) 400°C
(b) 100°C
(c) 800°C
(d) 600°C
Answer:
(c) 800°C

Question 17.
Rock salt is ………………………… in colour.
(a) black
(b) white
(c) brown
(d) blue
Answer:
(c) brown

Question 18.
Strong odour in swimming pool is due to ………………………… .
(a) chlorine gas
(b) impurities
(c) calcium carbonate
(d) calcium hydroxide
Answer:
(a) chlorine gas

Question 19.
Molecular formula of sodium bicarbonate is ………………………… .
(a) NaHCO₃
(b) Na₂HCO₃
(c) Na₂HCO₂
(d) NaHCO₂
Answer:
(a) NaHCO₃

Question 20.
Soap is ………………………… in nature.
(a) radioactive
(b) natural
(c) acidic
(d) basic
Answer:
(d) basic

Question 21.
The molecular formula for Magnesium bromide is ………………………… .
(а) MgBr
(b) MgBr₂
(c) Mg₂Br₂
(d) Mg₂Br
Answer:
(b) MgBr₂

Fill in the blanks and rewrite the complete statements:

(1) 25% of NaCl is known as
(2) gas is released when bleaching powder is added to water.
(3) Washing soda is as it absorbs moisture if left exposed to air.
(4) is used to make hard water soft.
(5) Molecular formula for Alum is
(6) is used in blood test for diagnosing anaemia.
(7) High grade of and are used as raw material to manufacture bathing soap.
(8) Pickles, jams and sauce contain small quantities of and
(9) Excessive consumption of foods with added food colours leads to diseases like
(10) Melting point of Teflon is
(11) Anodizing is done by
(12) The red blood cell count increases in the disease
(13) Magnesium sulphate (MgS04.7H20) is also called
Answer:
(1) Brine
(2) Chlorine
(3) hygroscopic
(4) Na₂CO₃ (Washing soda)
(5) K₂SO₄.Al₂(SO)₃.24H₂O
(6) Blue Vitriol
(7) fats, oils
(8) lead, mercury
(9) ADHD (Attention Deficit Hyperactivity Disorder)
(10) 327°C
(11) Electrolysis
(12) Polycythemia
(13) Epsom salt
(14) Soap

State whether the following statements are true or false. Correct the false statements.
(1) Bleaching powder is used in preparation of chloroform which is used as an anaesthetic.
(2) On addition of universal indicator the colour of table salt changes to pink.
(3) Borax is Na₂B₄O₇.9H₂O.
(4) Boron -10 is used to cure bone cancer.
(5) Clinical deo contains 20 to 25% of aluminium.
(6) NaHCO₃ is sodium carbonate.
(7) Soap is acidic in nature.
(8) Baking powder is neutral in nature.
(9) POP is crystalline in nature.
(10) pH value of universal indicator is 0 – 7.
(11) Sodium chloride is formed by neutralization reaction between sodium hydroxide and calcium carbonate.
(12) Boiling point of NaCl is 800 °C.
(13) Molten state of NaCl is also called as solid state.
(14) Mineral halite is an example of Rock Salt.
(15) Sodium bicarbonate is used to reduce acidity.
(16) Bleaching powder is also called as chloride of lime.
(17) Bleaching powder is obtained by reaction of chlorine gas with slaked lime.
(18) Bleaching powder available in market is classified on the basis of colour.
(19) The hard water becomes soft on adding baking soda (NaHCO₃)
Answer:
(1) True
(2) False. On addition of universal indicator the colour of table salt changes to green.
(3) False. Borax is Na₂B₄O₇.9H₂O
(4) False. Boron – 10 is used in treatment of brain tumour.
(5) True
(6) False. NaHCO₃ is sodium bicarbonate.
(7) False. Soap is basic in nature.
(8) False. Baking powder is basic in nature.
(9) False. POP is amorphous in nature.
(10) False. pH value of universal indicator is 0 -14.
(11) False. Sodium chloride is formed by a neutralization reaction between sodium hydroxide and hydrochloric acid.
(12) False. Melting point of NaCl is 800°C.
(13) False. Molten state of NaCl is also called as fused state.
(14) True
(15) True
(16) True
(17) True
(18) False. Bleaching powder available in market is classified on the basis of percentage of chlorine present in it.
(19) False. Hard water becomes soft on adding washing soda (Na₂CO₃.10H₂O)

Name the following:

Question 1.
Important salts found in sea water.
Answer:
Magnesium chloride, Potassium chloride

Question 2.
Chemical used in preparation of breads and cakes to make them soft.
Answer:
Sodium bicarbonate

Question 3.
Gas liberated when bleaching powder is added to CO₂ gas.
Answer:
Chlorine (Cl₂) gas.

Question 4.
Salt used in refining petroleum
Answer:
Sodium carbonate (Na₂CO₃)

Question 5.
Chemical formula of bleaching powder
Answer:
CaOCl₂

Question 6.
The chemical formula of Sodium hydrogen carbonate.
Answer:
NaHCO₃

Question 7.
Nature of soap.
Answer:
Basic

Question 8.
Molecular formula for Magnesium bromide
Answer:
MgBr₂

Question 9.
Melting point of NaCl
Answer:
800 °C

Question 10.
Two examples of Rock Salt
Answer:
Mineral halite and Himalayan rock salt.

Question 11.
Uses of sodium bicarbonate
Answer:
To prepare breads, cakes and dhokla

Question 12.
Constituents of baking powder.
Answer:
Baking soda and mild acid (tartaric acid)

Question 13.
Substance used to make hard water soft.
Answer:
Washing soda i.e. Na₂CO₃.10H₂O.

Question 14.
Radioactive isotopes used in treatment of bone cancer.
Answer:
Strontium – 89, Strontium – 90, Samarium -153, Radium – 223

Question 15.
Use of Strontium 89 and strontium 90.
Answer:
Treatment of bone cancer.

Select the odd man out:

Question 1.
Sodium sulphate, Barium chloride, Magnesium sulphate, Bleaching powder.
Answer:
Bleaching powder, all others are crystalline salt with water of crystallization while bleaching powder is not.

Question 2.
Strontium – 89, Strontium – 90, Radium – 223, Iodine -123.
Answer:
Iodine -123, it is used to cure hyperthyroidism while others are used to cure bone cancer.

Question 3.
Soap, Toothpaste, Baking soda, Curd.
Answer:
Curd, it is acidic in nature while others are basic in nature.

Question 4.
Na₂CO₃.10H₂O, Na₂SO₄.10H₂O, BaCl₂.2H₂O, CaOCl₂
Answer:
CaOCl₂, it is amorphous in nature while rest are crystalline in nature.

Question 5.
Boron-10, Iodine – 131, Cobalt – 60, Iodine – 123.
Answer:
Iodine -123, it is used in hyperthyroidism while rest are used in treatment of brain tumour.

Question 6.
Na₂SO₄, K₃PO₄, MgBr₂, HCl.
Answer:
HCl, rest all are salts but HCl is an acid.

Write the correlated terms:

(1) Washing Powder : Basic :: Milk : ……………………………
(2) Na₂SO₄: Sodium sulphate :: K₃PO₄ : ……………………………
(3) CaOCl₂: Calcium Oxychloride : : NaHCO₃ : ……………………………
(4) Borax : 10H₂O : : Alum : ……………………………
(5) Sodium Sulphate : Na₂SO₄.10H₂O : : Magnesium Sulphate : ……………………………
(6) Bathing soap : High grades fats and oils :: Washing soap : ……………………………
(7) Radium – 23 : Bone cancer :: Phosphorus – 32 : ……………………………
(8) Iodine -123 : Hyperthyroidism :: Iodine -131 : ……………………………
(9) Clinical deo : 20-25% of aluminium : : Antiperspirant deo : of aluminium chlorohydrate : ……………………………
(10) Sodium carbonate : Na₂CO₃ : : Sodium bicarbonate : ……………………………
(11) Curd : Acidic : : Soap : ……………………………
(12) Calcium Carbonate : CaCO₃ : : Magnesium bromide : ……………………………
(13) Baking Soda : NaHCO₃ : : Washing Soda : ……………………………
(14) Baking Soda : Breads and Cakes : : Washing Soda : ……………………………
(15) Borax : Na₂B₄O₇.10H₂O : : Alum : ……………………………
Answer:
(1) Acidic
(2) Potassium phosphate
(3) Sodium hydrogen carbonate
(4) 24H₂O
(5) MgSO₄.7H₂O
(6) Low-grade fats and oils
(7) Polycythemia
(8) Tumour detection
(9) 15%
(10) NaHCO.
(11) Basic
(12) MgBr₂
(13) Na2CO₃.10H₂O
(14) Hard water soft
(15) K₂SO₄.Al₂(SO₄)₃.24H₂O

Match the columns:

Question 1.

Column ‘A’	Column ‘B’
(1) Barium chloride	(a)	24H2O
(2) Sodium sulphate	(b)	7H2O
(3) Magnesium sulphate	(c)	2H2O
(4) Alum	(d)	10H2O

Answer:
(1 – c),
(2 – d),
(3 – b),
(4 – a)

Question 2.

Column ‘A’	Column ‘B’
(1) Strontium – 90	(a) Brain tumour
(2) Cobalt – 60	(b) Hyperthyroidism
(3) Iodine – 131	(c) Polycythemia
(4) Phosphorus – 32	(d) Bone cancer

Answer:
(1 – d),
(2 – a),
(3 – b),
(4 -c)

Give scientific reasons:

Question 1.
Baking soda is used while making cakes.
Answer:

• Baking soda is chemically known as sodium bicarbonate.
• On heating, sodium bicarbonate decomposes to form sodium carbonate, water and carbon dioxide (CO,).
• The carbon dioxide produced is released due to which the cake becomes soft and spongy.
• Hence, baking soda is used to make cake spongy and soft.

Question 2.
Baking soda is used to reduce acidity in the stomach.
Answer:

• Baking soda is used as a medicine (antacid). When it is taken, it undergoes hydrolysis to give sodium hydroxide in the stomach. Thus, sodium hydroxide neutralizes the hydrochloric acid produced by gastric juice and gives relief to the patient from acidity.
  

Question 3.
Tap water and water in swimming pool has a typical strong odour in the rainy season.
Answer:

• Tap water and water in swimming pool has a typical strong odour in the rainy season, it is the odour of the chlorine gas that is used to destroy the microbes in the water.
• Chlorine gas is a strong oxidizing agent and therefore, it has a strong disinfecting as well as bleaching action.
• Chlorine is inconvenient to handle because of its gaseous state. Instead, the solid bleaching powder which has the same effect is more convenient to use.
• Bleaching powder undergoes slow decomposition due to the carbon dioxide in air and chlorine gas is released. Bleaching powder gets its property because of this release of chlorine gas.
  

Question 4.
Sodium carbonate is added to hard water to make it soft.
Answer:

• The hardness of water is due to the presence of chlorides and sulphates of calcium and magnesium in it.
• Na₂CO₃ is added to it to soften such water and make it suitable for use.
• The reaction with Na₂CO₃ causes the formation of insoluble carbonate salts of magnesium and calcium thus making the water soft.
  

Question 5.
Alum is used in the process of water purification.
Answer:

• Alum is used in the process of water purification because of property of coagulation.
• The solid impurities in water come together, become heavy and settle to the bottom.
• As a result, the water above becomes clear.

Question 6.
Overconsumption of artificial food colours should be avoided?
Answer:

• The overconsumption of artificial food colours should be avoided because they can be detrimental to health.
• Food colours added to pickles, jam and sauce contain small quantities of lead and mercury. These can be harmful for those who consume these products on a regular basis.
• Diseases like ADHD (Attention Deficit Hyperactivity Disorder) can affect children due to excessive consumption of foods with added food colours.

Question 7.
Artificial colours in Rang Panchami should be used cautiously.
Answer:

• We regularly use artificial colours on Rang Panchami.
• The red colour used on Rang Panchami is very dangerous. It contains a high proportion of mercury in it.
• This poses risks like blindness, skin cancer, asthma, itching of the skin, permanent blocking of sweat pores etc.
• Therefore, it is necessary that artificial colours are used cautiously.

Question 8.
There are various brands of bleaching powder in the market.
Answer:

• When bleaching powder comes in contact with air, it reacts with carbon dioxide to form calcium carbonate and releases chlorine gas. CaOCl₂ + CO₂ → CaCO₃ + Cl₂ ↑ (from air)
• This generated chlorine is known as “available chlorine.”
• On the basis of the percentage of “available chlorine” various brands of bleaching powder are available in the market.

Question 9.
We use anodized cooking utensils like griddles and cookers.
Answer:

• Anodizing is process of forming a protective rayer of hydrated aluminium oxide on utensils.
• Due to anodizing, the surface of the cooking utensils become non-standing, non-toxic and non-reactive with the ingredients of the foot.
• These utensils get heated faster and withstand high heat.
• Also the amount of butter, ghee or oil used to cook food in these type of utensils is neglible.
• These utensils are tough, durable and resistant to corrosion.
• Hence, we use anodized cooking utensils like gridders and cookers.

Explain the following chemical reactions with the help of balanced equations :

Question 1.
Sodium hydroxide reacts with dilute Hydrochloric acid.
Answer:
When Sodium hydroxide reacts with dilute Hydrochloric acid, it forms sodium chloride and water.
This is a neutralization reaction.

Question 2.
When an electric current is passed through a saturated solution of sodium chloride (brine)
Answer:
When an electric current is passed through a saturated solution of sodium chloride (brine) it is electrolysed and hydrogen gas is released at the cathode while chlorine gas is released at the anode. Also, an important basic compound NaOH is formed in the cell.

Question 3.
Baking soda (Sodium hydrogen carbonate) reacts with dilute hydrochloric acid.
Answer:
When Sodium bicarbonate (Sodium hydrogen carbonate) reacts with dilute hydrochloric acid, it gives sodium chloride, water and carbon dioxide gas is liberated.

Question 4.
Bleaching powder is exposed to air.
Answer:
When bleaching powder is exposed to air, it undergoes slow decomposition due to the carbon dioxide in air and chlorine gas is released.

Question 5.
When dry slaked lime reacts with chlorine gas.
Answer:
When dry slaked lime reacts with chlorine gas, it gives bleaching powder.

Question 6.
Bleaching powder reacts with dilute sulphuric acid.
Answer:
Dilute sulphuric acid reacts rapidly with bleaching powder to form calcium sulphate and release chlorine gas completely.

Question 7.
Bleaching powder reacts with dilute hydrochloric acid.
Answer:
Dilute hydrochloric acid reacts rapidly with bleaching powder to form Calcium chloride and release chlorine gas completely.

Question 8.
Sodium carbonate reacts with magnesium chloride.
Answer:
When Sodium carbonate reacts with magnesium chloride, it forms insoluble magnesium carbonate and sodium chloride. This reaction is used to make hard water soft.

Question 9.
Crystalline sodium carbonate is exposed to air.
Answer:
When crystalline sodium carbonate is exposed to air it loses its water of crystallization readily and a white powder is obtained. This powder is called washing soda.

Question 10.
Sodium carbonate reacts with sulphuric acid.
Answer:
When sodium carbonate reacts with sulphuric acid it forms sodium sulphate, water and carbon dioxide gas is liberated.

Distinguish between;

Question 1.
Washing soda and Baking soda
Answer:

Washing soda	Baking soda
(i) Chemical name is sodium carbonate.	(i)    Chemical name is sodium bicarbonate or sodium hydrogen carbonate.
(ii) Its molecular formula is Na2CO3.10H2O	(ii) Its molecular formula is NaHCO3
(iii) It is a crystalline substance.	(iii) It is an amorphous powder.
(iv) It is used in manufacturing soaps and detergents.	(iv) It is used in bakery for making cakes and bread lighter and spongy.

Question 2.
Bathing soap and Washing soap
Answer:

Bathing soap	Washing soap
(i) High-grade fats and oils are used as the raw material.	(i) Low-grade fats and oils are used as the raw material.
(ii) Expensive perfumes added.	(ii) Cheaper perfumes added.
(iii) No free alkali content present to prevent injuries to skin.	(iii) Free alkali present for cleaning action.

Answer the following:

Question 1.
Give the properties and uses of Sodium bicarbonate.
Answer:
Properties and uses of sodium bicarbonate

• (i) NaHCO₂ reacts with moist litmus paper and red litmus turns blue which means that it is basic in nature.
• (ii) It is used to make bread, cake, dhokla.
• (iii) Being basic in nature it is used to reduce acidity in the stomach.
• (iv) NaHCO₃ is used to make the active substance CO₂ in the fire extinguisher.
• (v) Baking soda is used to clean an oven.

Question 2.
Give the properties and uses of washing soda.
Answer:
Properties and uses of washing soda :

• Washing soda is a whitish and odourless powder at room temperature.
• Litmus has a blue colour in its aqueous solution.
• It is hygroscopic, that is, it absorbs moisture if left exposed to air.
• It is used mainly for washing clothes.
• Sodium carbonate is used in the glass and paper industry and also in refining of petrol.

Question 3.
Name some substances in our daily use which contain water of crystallization.
Answer:

• Alum (Potash alum – K₂SO₄.Al₂(SO₄)₃.24H₂O)
• Borax (Na₂B₄O₇.10H₂O)
• Epsom salt (Magnesium sulphate MgSO₄.7H₂O)
• Barium chloride (BaCl₂.2H₂O)
• Sodium sulphate (Glauber’s salt Na₂SO₄.10H₂O)

Question 4.
Give the uses of radioactive isotopes in the measurement of thickness, density and level.
Answer:
Measurement of thickness, density and level:

• It is necessary to maintain the required thickness in the manufacture of aluminium, plastic, iron sheets of differing thickness.
• In the manufacturing process, a radioactive substance is placed on one side and an instrument to measure radiation on the other.
• The radiation read by the measuring instrument varies with the thickness of the sheet.
• Material inside a packing can also be examined by the same technique.

Question 5.
Give the uses of radioactive isotopes in Luminescent paint and radioluminescence.
Answer:
Luminescent paint and radioluminescence:

• The radioactive substances radium, promethium, tritium with some phosphour are used to make certain objects visible in the dark, for example, the hands of a clock, and certain other objects.
• Krypton-85 is used in HID (High Intensity Discharge) lamps while promethium-147 is used in portable X-ray units as the source of beta rays.

Question 6.
Give the uses of radioactive isotopes in Field of agriculture.
Answer:
Field of agriculture:

• The genes and chromosomes that give seeds properties like fast growth, higher productivity, etc. can be modified by means of radiation.
• The radioactive isotope cobalt-60 is used for food preservation.
• Onions, potatoes are irradiated with gamma rays from cobalt-60 to prevent their sprouting.
• Strontium-90 is used as a tracer in the research on various crops.

Question 7.
Give the uses of dyes.
Answer:
Uses of dyes :

• They are used for colouring cloth and hair.
• Fluorescent colours are used to make street boards that are visible at night.
• Dyes are used to polish leather shoes, purses and chappals.

Question 8.
What are the adverse effects of dyes?
Answer:
Adverse effects dyes :

• Dyeing hair can have adverse effects like hair fall, damage to hair texture, burning of skin, adverse effect on eyes, etc.
• Lipstick contains a dye named carmine. It does not affect lips but causes stomach disorders.
• Excessive use of plants for making natural dyes results in deterioration of the environment.

Question 9.
Give the uses of teflon.
Answer:
Uses of teflon :

• Teflon is a poor conductor of electricity. Therefore, Teflon clad wires and parts are used in high technology electronic instruments.
• It is used for making non-stick kitchenware.
• The coloured metal sheets of two-wheelers and four-wheelers are given a Teflon coating to protect them from damage due to high temperature and rain.

Question 10.
What is ceramic? Give examples.
Answer:

• Ceramic is a heat resistant substance formed by kneading an inorganic substance in water and then shaping it and hardening it by heating.
• Pots made by a potter, Mangalore roofing tiles, construction bricks, pottery, terracotta articles are some examples of common ceramic articles that we see around.

Question 11.
Give the uses of ceramics.
Answer:

• Ceramics can withstand high temperatures without decomposing. Ceramic is brittle, water-resistant and an electrical insulator.
• Therefore, it is used in electrical instruments, for coating the interior of a kiln, the outer surfaces of ships and blades of jet engines.
• A certain type of ceramic tiles are fixed on the outer layer of a space shuttle. Some types of ceramics are used as superconductors.

Question 12.
What is brine? What happens when ^th of this solution is evaporated?
Answer:

• The 25% aqueous solution of salt is called saturated brine.
• When th of this solution is evaporated the dissolved salt gets crystallized and salt gets separated from the solution.

Question 13.
What is baking soda? Give its chemical name and molecular formula.
Answer:

• Baking soda is a white non-crystalline powder.
• Its chemical name is sodium hydrogen carbonate or sodium bicarbonate and its molecular formula is NaHC03.

Question 14.
Give two uses of Blue vitriol.
Answer:

• Blue vitriol is used in the blood test for diagnosing anaemia.
• Bordeaux mixture which is a mixture of slaked lime and blue vitriol is used as a fungicide on fruits like grapes and musk melon.

Question 15.
What is radioactivity and what are radioactive substances?
Answer:

• Elements with a high atomic number such as uranium, thorium, radium have a property of spontaneously emitting invisible, highly penetrating and high energy radiation. This property is called radioactivity.
• A substance having this property is called a radioactive substance.

Question 16.
What can you say about the uses of radioactive isotopes?
Answer:

• It is a misconception that radioactive elements are used only for making an atom bomb.
• Radioactive isotopes are used in various fields such as scientific research, agriculture, industry, medicine, etc.
• Radioactive substances are used in two ways.
• By using the radiation alone.
• By using the radioactive element itself.

Question 17.
Give the uses of radioactive isotopes in Radiography.
Answer:

• Internal cracks and voids in cast iron articles and iron solder can be detected with the help of gamma rays.
• For this purpose, isotopes like cobalt-60, iridium-192 are used in the radiography camera.
• This technique is used for detecting flaws in metalwork.

Question 18.
Give the uses of radioactive isotopes in ceramic articles.
Answer:

• Luminous colours are used to decorate ceramic tiles, utensils, plates, etc.
• Earlier uranium oxide was used in these paints.

Question 19.
What is a dye?
Answer:
The coloured substance which on applying to an article, imparts that colour to the article, is called a dye

Question 20.
What is done to fix a dye on the cloth ?
Answer:

• A mordant is to be used to fix the colour after dyeing a cloth.
• A mordant is a chemical binding agent that adheres well to both the fibers and the dye.

Question 21.
What is Teflon? Give its chemical name.
Answer:

• Teflon is the polymer of tetrafluoroethylene.
• Its chemical name is polytetrafluoroethylene (C₂F₄)_n

Question 22.
What is powder coating? Why is it done?
Answer:

• Powder coating is a method of applying a layer harder than paint on the surface of plastic, medium density fibre (MDF).
• Board and iron object to make them attractive, durable and to prevent rustihg respectively.

Question 23.
Give the properties of ceramics.
Answer:

• Ceramics can withstand high temperatures without decomposing.
• Ceramic is brittle, water resistant and an electrical insulator.

Question 24.
How is bone china made? How is it different from porcelain?
Answer:

• Bone china is made by adding some ash of animal bones in the mixture of china clay, feldspar and fine silica while making porcelain.
• This ceramic is harder than porcelain.

Question 25.
What compounds are used instead of clay for making advanced ceramic?
Answer:
Oxides like Alumina (Al₂O₃), Zirconia (ZrO₂) Silica (SiO₂) and some other compounds like silicon carbide (SiC), boron carbide (B₄C) are used instead of clay for making advanced ceramic.

Question 26.

What is sintering?
Answer:

• Advanced ceramics requires a temperature of 1600 to 1800 °C and an oxygen-free atmosphere for firing.
• This process is called sintering.

Write short notes on :

Question 1.
Chernobyl disaster.
Answer:

• On 26th April 1986, the graphite reactor in the Chernobyl atomic power plant exploded, and suddenly the radioactive isotopes and radiation came out.
• Due to this episode, radioactive isotopes entered the human body through water and land and caused genetic disorders.
• These got carried further into the next generation.
• Thyroid disorders increased in children as well as adults.
• As a result, the incidence of throat diseases is greater there than in other places.

Question 2.
Food colours.
Answer:

• Food colours are mixed in most soft drinks and foodstuffs available in the market.
• These food colours are in the form of powders, gels and pastes.
• Food colours are used in domestic as well as commercial products.
• Certain colours and essences are added to ice cream, ice candies, sauces, fruit juices, cold drinks, pickles, jams and jellies.
• Food colours are often found to be added to packaged meat (chicken, mutton), chilli powder, turmeric, sweets and other similar substances so as to give them a good colour.
• Food colours are natural as well as artificial.
• The food colours prepared from seeds, beetroot, flowers and fruit concentrate are natural.
• Tetrazene, sunset yellow are artificial food colours used extensively.
• However, over-consumption of artificial food colours can be detrimental to health. Therefore, usage of natural food colours is always good.

Question 3.
Anodizing.
Answer:

• A protective layer is formed naturally on the surface of aluminium metal by reaction with oxygen in air.
• In the anodizing process, this layer can be made of the desired thickness.
• Anodizing is done by electrolysis.
• Dilute sulphuric acid is taken in the electrolytic cell and the aluminium article is dipped in it as the anode.
• When an electric current is passed, hydrogen gas is released at the cathode and oxygen gas at the anode.
• A reaction with oxygen occurs and a layer of hydrated aluminium oxide is formed on the anode, i.e. the aluminium article.
• This layer can be made attractive by adding colour in the cell during electrolysis.

Answer the following questions:

Question 1.
What are salts? Give their source.
Answer:

• The ionic compounds which do not contain H+ and OH ions and contain only one kind of cation and anion are called simple salts.
• For example, Na₂SO₄, K₃PO₄, CaCl₂.
• The sea is said to be a rich source of salts of various elements such as chlorine, sodium, magnesium, potassium, calcium, bromine.
• The important salts found in sea water are:
  (a) Sodium chloride
  (b) Magnesium chloride
  (c) Magnesium sulphate
  (d) Potassium chloride
  (e) Calcium carbonate
  (f) Magnesium bromide

Question 2.
Which are the three kinds of salts depending on their pH value? How are they formed?
Answer:
The three kinds of salts depending on their pH value are:

Neutral salts:
Salt is neutral when its pH value is 7. Such a salt is made from a strong acid and a strong base.

Acidic salts:
The pH value of a salt made from a strong acid and a weak base is less than 7 and it is acidic.

Basic salts:
The pH value of a salt made from a weak acid and strong base is more than 7 and it is basic.

Question 3.
Which is the most used salt? What is its chemical name? How is it formed?
Answer:

• Table salt, or common salt, which gives a salty taste to food, is the most used of all salts.
• Its chemical name is Sodium chloride.
• Sodium chloride is formed by a neutralization reaction between sodium hydroxide and hydrochloric acid.
• Chemical reaction
• This is a neutral salt and the pH value of its aqueous solution is 7.

Question 4.
How is bleaching powder obtained?
Answer:

• Bleaching powder is obtained by the reaction of chlorine gas with slaked lime.
• Chemical reaction

Question 5.
How is hard water from well converted to soft water?
Answer:

• The hard water from a well or a bore-well becomes soft on adding washing soda and we come to know this from the lather formed on it.
• The hardness of water is due to the presence of chlorides and sulphates of calcium and magnesium in it.
• Na₂CO₃ is added to it to soften such water and make it suitable for use.
• The reaction with Na₂CO₃ causes the formation of insoluble carbonate salts of magnesium and calcium.
• Chemical reaction
  MgCl_2(aq) + Na₂CO_3(s) → MgCO_3(s) + 2NaCl_(s) Magnesium Sodium Magnesium Sodium chloride carbonate carbonate chloride

Question 6.
How is washing soda obtained from sodium carbonate?
Answer:

• Sodium carbonate is a water soluble salt of sodium.
• Crystalline sodium carbonate, on keeping, loses its water of crystallization readily and a white powder is obtained.
• This powder is called washing soda.
• Chemical reaction

Question 7.
How is soap prepared? Why it does not form lather with hard water?
Answer:

• When oil or animal fat is boiled with an aqueous solution of sodium or potassium hydroxide, sodium or potassium salts of carboxylic acids (fatty acids) are formed.
• These salts are called soap.
• When soap is mixed with hard water, calcium and magnesium salts of fatty acids are formed.
• These being water insoluble, they form a precipitate and that is why lather is not formed.

Question 8.
What are the harmful effects of artificial food colours?
Answer:

• Food colours added to pickles, jams and sauces contain small quantities of lead and mercury. These can be harmful for those who consume these products on a regular basis.
• Diseases like ADHD (Attention Deficit Hyperactivity Disorder) can affect children due to excessive consumption of foods with added food colours.

Question 9.
Which is the main source of colour for preparing a natural dye?
Answer:

• Plants are the main source of colour for preparing a natural dye.
• Roots, leaves, flowers, bark, fruits, seeds, fungus and pistils are used for making dyes.
• In Kashmir a very good dye is made from saffron, which is used to dye fibers from which saris, shawls and dresses are made.
• These are very costly. The use of henna leaves to colour hair is safe for health.

Question 10.
How are artificial colours harmful to us?
Answer:

• We regularly use artificial colours on Rang Panchami.
• The red colour used on Rang Panchami is very dangerous.
• It contains a high proportion of mercury in it.
• This poses risks like blindness, skin cancer, asthma, itching of the skin, permanent blocking of sweat pores, etc.
• Therefore, it is necessary that artificial colours are used cautiously.

Question 11.
What are the harmful effects of deodorants?
Answer:

• Aluminium – Zirconium compounds are the most harmful chemicals in deodorants. Disorders like headache, asthma, respiratory disorders, heart disease are likely to occur without our knowledge.
• There is a possibility of various skin disorders and also skin cancer due to the aluminium chlorohydrates.

Question 12.
How is a ceramic article made?
Answer:

• When clay is kneaded in water, shaped and then fired in a kiln at a temperature of 1000 to 1150 °C, a porous ceramic is formed.
• To overcome the porosity, the fired object is covered with finely ground glass powder suspended in water (glaze) and is then fired again. As a result, the surface of the ceramic becomes shiny and its porosity disappears.

Question 13.
What is porcelain? How is it made?
Answer:

1. Porcelain is a hard, translucent and white coloured ceramic. It is made by using the white clay called kaolin, found in China. Glass, granite and the mineral feldspar is mixed with kaolin and kneaded with water.
2. The resulting mixture is shaped and fired in a kiln at a temperature of 1200 to 1450 °C. On firing again after glazing, beautiful articles of porcelain are obtained.

Answer the following questions:

Question 1.
What are the constituents of baking powder? Where is the baking powder used?
Answer:

• Baking powder consist of 30% sodium bicarbonate, 5-12% monocalcium phosphate and 21-26% sodium aluminium sulphate.
• Baking powder is a leavening agent and is used for increasing the volume and lightening the texture of baked goods.

Question 2.
Take a piece of coloured cloth. Put some saturated solution of bleaching powder on a small part and observe what changes take place in the colour of the cloth.
Answer:
When bleaching powder is added to a piece of coloured cloth, the fabric looses its colour due to the oxidising reaction of the chlorine present in the bleaching powder.

Answer in detail:

Question 1.
Give the properties and uses of Sodium chloride.
Answer:
Properties and uses of sodium chloride:

• Common salt is a colourless and crystalline ionic compound. There is no water of crystallization in its crystalline structure.
• It is a neutral salt, salty in taste.
• This compound is used for the production of salts like Na₂CO₃, NaHCO₃.
• When an electric current is passed through a saturated solution of sodium chloride (brine), it is electrolysed and hydrogen gas is released at the cathode while chlorine gas is released at the anode.
• This method is used for production of chlorine gas. In this method an important basic compound NaOH is formed in the cell.
  2NaCl + 2H₂O → 2NaOH + Cl₂↑ + H₂↑
• When salt is heated to a high temperature (about 800 °C), it melts. This is called the fused state of the salt.
• When fused salt is electrolysed, chlorine gas is released at the anode and liquid sodium metal, at the cathode.

Question 2.
Give the properties and uses of Bleaching Powder.
Answer:
Properties and uses bleaching powder:

• Bleaching powder is a yellowish-white coloured solid substance.
• Its chemical name is Calcium oxychloride.
• It has a strong odour of chlorine gas.
• It is used for disinfection of drinking water at the water works and the water in the swimming pool.
• It is used for bleaching of cloth.
• It is used for disinfection by the road side and garbage sites.
• Dilute sulphuric acid and dilute hydrochloric acid react rapidly with bleaching powder to release chlorine gas completely.
  CaOCl₂ + H₂SO₄ → CaSO₄ + Cl₂ ↑ + H₂O CaOCl₂ + 2HCl → CaCl₂ + Cl₂ ↑ + H₂O
• Calcium oxychloride reacts slowly with carbon dioxide to form calcium carbonate and chlorine.
  CaOCl₂ + CO₂ → CaCOs + Cl₂ ↑

Question 3.
Explain with neat labelled diagram the nature of radioactive radiation.

Answer:

• When radioactive radiations are allowed to pass through two oppositely charged plates they get separated. This method was introduced by Rutherford in 1902.
• Rutherford and Willard studied the radiation emitted by radioactive substances.
• For this purpose, the rays were allowed to pass through an electrical field and a photographic plate was held in their path.
• It was found that the radiation was divided into three types.
• One type of radiation deviated slightly towards the negatively charged plate, while the second type of radiation deviated substantially towards the positively charged plate.
• However, the third type of radiation did not deviate at all in the electrical field.
• The rays which deviated slightly toward negatively charged plate are called alpha rays.
• Those which deviate substantially towards the positively charged plate are called beta rays and those which did not deviate at all are called gamma rays.

Question 4.
Give the characteristics of alpha, beta and gamma rays.
Answer:
Characteristics of alpha, beta and gamma rays are as given in the table.

Question 5.
Give the uses of radioactive isotopes in Medical science.
Answer:
Medical science:

• Polycythemia: The red blood cell count increases in the disease polycythemia. Phosphorus- 32 is used in its treatment.
• Bone cancer: Strontium-89, strontium-90, samarium-153 and radium-223 are used in the treatment of bone cancer.
• Hyperthyroidism: Enlargement of thyroid gland, weight loss in spite of appetite, insomnia are the symptoms of hyperthyroidism.
• It occurs due to overproduction of hormones by the thyroid gland. Iodine-123 is used in the treatment of hyperthyroidism.
• Tumour detection: Boron-10, iodine-131, cobalt-60 are used in the treatment of brain tumour, while arsenic-74 is used in detection of small tumours in the body.

Question 6.
What are the hazards of radioactive substances and radiation?
Answer:

• The central nervous system is affected by radioactive radiations.
• Hereditary defects are generated by bombardment of radiation on D.N.A in the body.
• Radioactive radiation can penetrate the skin, and causes diseases like skin cancer, leukemia.
• The radiative pollutants created due to explosions enter the body through air and it is difficult to control them.
• The radioactive pollutants released in the sea enter the bodies of fishes and through them enter the human body.
• The radioactive paint on the watch can cause cancer.
• The radioactive isotopes strontium-90 can enter the body through plants, fruits, flowers, cereals, milk, etc. and cause diseases like bone cancer, leukemia.

Question 7.
Why are deodorant used? Give their types and content.
Answer:

• Body odour is caused by the bacterial decomposition of the sweat. A deodorant is used to prevent this odour.
• Deodorants contain parabens (methyl, ethyl, propyl, benzyl and butyl) and also alcohol in large proportions. Aluminium compounds and silica are also used.
• Types of deodorants are :
  (a) Ordinary deo: It contains a smaller proportion of aluminium. It decreases the odour of the sweat.
  (b) Antiperspirant deo : This decreases the extent of sweating. It contains about 15% of aluminium chlorohydrate. It clogs the sweat pores on the skin.
  (c) Clinical deo : Some people sweat heavily and it has harmful effects on the skin. Clinical deo is meant for such people. It contains 20 to 25% aluminium. It is used during the night.

Question 8.
Explain how powder coating is done.
Answer:

• Powder coating is a method of applying a layer harder than paint on the surface of an iron object to prevent rusting.
• In this method, a polymer resin, a pigment and some other ingredients are melt, mixed, cooled and ground into a uniform powder.
• This powder is sprayed on the polished metal surface by electrostatic spray deposition (ESD).
• In this method, the particles of the powder are given an electrostatic charge due to which a uniform layer of the powder sticks to the metal surface.
• Then the object is heated in the oven along with the coating.
• A chemical reaction occurs in the layer, resulting in the formation of long cross-linked polymeric chains.
• This powder coating is highly durable, hard and attractive.
• Powder coating can be done on plastic and medium density fibre (MDF) board in day to day use as well.

 

Balbharti Maharashtra State Board Class 9 Political Science Solutions Chapter 5 India and Other Countries Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 9 Political Science Solutions Chapter 5 India and Other Countries

Class 9 Political Science Chapter 5 India and Other Countries Textbook Questions and Answers

1. Choose the right option and rewrite the sentence:

Question 1.
The country that has a free international border with India _______.
(a) Pakistan
(b) Bangladesh
(c) Nepal
(d) Myanmar
Answer:
(c) Nepal

Question 2.
The countries that have tense relations with India _______.
(a) Pakistan and China
(b) Nepal and Bhutan
(c) Myanmar and Maldives
(d) Afghanistan and America
Answer:
(a) Pakistan and China

Question 3.
Factors that have an influence on the relations between India and Pakistan _____.
(a) Difference in the world view of both the countries
(b) Kashmir issue
(c) Nuclear Rivalry
(d) All of the above
Answer:
(d) All of the above

2. Explain with reasons whether the following statements are true or false:

Question 1.
India has an important position among the South Asian countries.
Answer:
True.

• India’s position in Asia is geographically and politically important.
• Afghanistan, Pakistan, Sri Lanka, Bangladesh, Myanmar, Nepal, Bhutan, China and Maldives are India’s neighbours.
• The values of equality and mutual respect have a great importance in India’s foreign policy. India has established relations with neighbouring countries on the basis of these values.
• India is the biggest country in the Indian subcontinent. Similarly, India is economically and technologically more advanced. It is thus natural that India has a great influence among the South Asian countries.

Question 2.
Sino-Indian relations are friendly.
Answer:
False.

• The conflict between India and China is connected to two issues : (a) Border issue and (b) The status of Tibet.
• The border dispute between India and China is related to the Aksai Chin area and the Macmahon line.
• China claims that the area, South of Aksai Chin and Macmahon line (Arunachal Pradesh) is Chinese Territory. China is not willing to agree that Macmahon Line is an international border.
• India made several efforts to sort this border dispute by means of dialogue, but it has not met with much success. In 1962, China Attacked India.
• When China was stepping up its military control in Tibet, Dalai Lama took asylum in India. This issue has been responsible for the conflict between the two countries.

Question 3.
India sent a peacekeeping force to help the Sri Lankan government.
Answer:
True.

• India has friendly relations with the southern neighbour Sri Lanka.
• Political instability in Sri Lanka after 1985 was a result of the differences between the Tamil and the Sri Lankan Government. At that time,
  India had sent a peace keeping force to help the Sri Lankan government.
• Friendly relations with Sri Lanka are important from the point of view of security in the Indian Ocean.

3. Complete the following chart.

Question 1.

Treaties/Exchanges	Countries
…………..	India and Pakistan
Macmahon Line	……………..
…………………	India and Bangladesh
Import of natural gas	…………..
…………..	India and Africa

Answer:

Treaties/Exchanges	Countries
Shimla Agreement, Tashkent Agreement	India and Pakistan
Macmahon Line	India and China
Treaties about sharing river waters and borders	India and Bangladesh
Import of natural gas	Myanmar
Civil Nuclear Agreement	India and Africa

4. Write short notes :

Question 1.
Shimla Agreement
Answer:
(i) India tried to solve Indo-Pak conflict bi-laterally. The Shimla Agreement of 1972 was based on these principles.

(ii) Pakistan considers Kashmir as the biggest hurdle in establishing relations with India.

(iii) The first Indo-Pak war took place in 1965, over Kashmir. The Tashkent Agreement was signed in 1966, but nothing much came out of it.

(iv) Even though the 1971 war was about the creation of Bangladesh, it also had the dimension of the Kashmir problem to it.

(v) The Shimla Agreement in 1972 provided a new format to the interaction between India and Pakistan.

Question 2.
Indo-Nepalese Friendship Treaty
Answer:
(i) The foundation of friendship between India and Nepal was laid with Indo-Nepalese Friendship Treaty in 1950.

(ii) According to this treaty, Nepalese citizens can not only enter India, but they are also permitted to take up government jobs and carry on trade in India.

(iii) The year 1990 marked the beginning of Nepal’s transition to democracy.

(iv) Nepal is dependent upon India for economic progress, basic facilities, food related needs, trade and energy needs.

(v) India sent a lot of help to Nepal at the time of the 2015 earthquake.

Question 3.
MacMahonLine
Answer:
(i) The conflict between India and China is connected to two issues :

• Border issue
• The status of Tibet

(ii) The border dispute between India and China is related to Aksai Chin area and the Macmahon line.
(iii) China claims that the area South of Aksai Chin and Macmahon line (Arunachal Pradesh) is Chinese Territory.
(iv) China is not willing to agree that Macmahon Line is an international border.
(v) India made several efforts to sort this border dispute by means of dialogue, but it has not met with much success.
(vi) In 1962, China attacked India.

Question 4.
Indo-Afghanistan Relation
Answer:
(i) There is a lot of political instability in Afghanistan.

(ii) The dominance of the terrorist organisation, Taliban is responsible for this.

(iii) India has extended help to bring peace, security and stability, curb violence and establish a democratic government.

(iv) Similarly, India is also helping Afghanistan in re-establishing communication facilities that have got destroyed due to war, build roads, cooperate in the fields of science and technology, build schools, health facilities and irrigation projects.

5. Answer the following questions in brief:

Question 1.
Explain the background of cooperative relations between India and America.
Answer:
India and America are two powerful nations who have democratic political systems. Right from the beginning, America was India’s most important trading partner.

(i) Many Indians have gone to America for education or work. Due to the presence of these non-resident Indians, the cultural, social and economic relations between America and India have been increasing.

(ii) After the end of Cold War, the military relations between India and America have increased on a large scale.

(iii) After India accepted free market economy, the speed of economic progress slowly increased. It resulted in further strengthening the trade relations between India and America.

(iv) When India conducted nuclear tests in 1998, there was tension in the relations between the two countries.

(v) Many rounds of discussions took place after that to improve the relations. Through these rounds of talks, America came to believe that India will use its nuclear weapons with responsibility. This completely transformed the Indo-American relations.

(vi) The Civil Nuclear Agreement signed in 2005 that was approved by the U.S. Congress in 2008 was an important landmark in Indo-American relations.

Question 2.
Give some information about the efforts taken by India for the establishment of democracy in neighbouring countries with examples.
Answer:
India upheld sovereignty and democratic values in Nepal, Afghanistan, Sri Lanka and Pakistan.

(i) Nepal was a Hindu Kingdom which adopted democratic government in 2006. India backed up its decision of adopting popular rule by helping Nepal with constitutional guidelines.

(ii) India also extended friendly relations to Ashraf Ghani through SAARC and other international platforms after the collapse of Taliban there.

(iii) India sent a peacekeeping force to Sri Lanka to bring about a cease fire between Sinhalese and Tamils and enforce peace and democracy.

(iv) The regime of Pervez Musharraf had adopted aggressive foreign policies and oppressed public opinion in Pakistan which led to violence and chaos. India had also criticised military rule in Pakistan.

Question 3.
What is the role of South Asian Association for Regional Cooperation?
Answer:
SAARC is a regional organisation established by the South Asian countries in 1985.

(i) The aim of this organisation is to encourage economic co-operation between South Asian nations and thereby achieve the development of the South Asian region.

(ii) The organisation of SAARC is a platform for South Asian countries to come together and discuss common questions and interests.

(iii) Some common interests of South Asian countries are alleviation of poverty, development of agriculture and technological revolution.

(iv) Some treaties were signed on the SAARC platform to make it easy for South Asian countries to trade with each other.

(v) As a part of this, it has been decided that South Asia should be made into a free trade area. For an equitable development of South Asian nations, a treaty about forming South Asian Free Trade Area was signed and South Asian University was established.

6. Give your own opinion about :

Question 1.
What remedies would you suggest in order to reduce the tensions in the relations between India and Pakistan?
Answer:
(i) To reduce tensions in the relations between India and Pakistan, I suggest that

(ii) Cultural exchange between the two nations must be enhanced by allowing and inviting artists of these nations to perform in each other’s countries. Films and sports would also work wonders to improve relations between them.

(iii) Since India is the largest democracy in the world, it should assist and uphold establishment of democratic systems in Pakistan, where government is either overpowered or practically governed by military.

(iv) Pakistan should be convinced through world opinion at international summits, conferences and organisations such as the UN.

(v) India should ascertain that the media does not mislead people in both the nations, by telecasting exaggerated content which might negatively influence the relations.

(vi) India should appeal the Pakistani Government for preservation of Hindu and Sikh pilgrimage places and cultural sites. India must also promote tourism in both the countries, so that civilians across borders have cordial relations.

(vii) Incidents of cross-border terrorism, violence and infiltration must be taken to international forums. Government of India should frame suitable policies for retrieval of Indian subjects, Prisoners of War and fishermen held in captivity of Pakistani Government.

Question 2.
Do you agree with the statement: ‘Hurdles are created in the way of internal development due to tense relations of India with neighbouring countries/ Explain with reasons.
Answer:
(i) Yes, I agree that hurdles are created in the way of internal development due to tense relations of India with neighbouring countries. Due to tense relations with the neighbours, India is unable to focus on the internal law and order situation and social welfare.

(ii) Non-cordial relations with the neighbours will force India to embark on military and nuclear mobilisation to retaliate the pressure of foreign aggression. This might culminate into a war.

(iii) War with neighbours will disturb the peace in the Indian subcontinent and compel India to divert its resources and efforts towards defence and manufacturing weapons.

(iv) Money and resources which should be invested for constructive purposes like health, education and infrastructure would be diverted towards destruction.

(v) A war with her neighbours can put tremendous pressure on India’s economy giving rise to problems like scarcity and inflation.

Question 3.
Do you think that strong healthy relations of India with America are conducive to India’s economic development?
Answer:
(i) Yes, I believe that strong healthy relations of India with America are conducive to India’s economic development.

(ii) America is an undisputable super power of the world and India is on its way to become a super power. Co-operation between these two countries can thwart terrorism in the world, which is a big challenge in the path of economic development.

(iii) Both countries follow democratic systems of government and free market economies. Co-operation from America is a must to enhance India’s economic prospects.

(iv) The non-resident Indians in America have helped to improve on Indian Foreign Reserves. With Indians taking up more employment in America, India can boost its foreign exchange.

(v) Call centres of American MNCs and other ways of outsourcing have provided employment opportunities to the Indian youth. American companies such as Coca Cola, Colgate and MacDonald established their franchises in India, whereas Indian IITians have dominated the Silicon Valley. An Indian – Sundar Pichai, today is the CEO of ‘Google’ – an American company.

(vi) As American companies find Indian economy very promising, FDI has also increased. The ’Make in India’ drive is now seeking empowerment of Indian economy and employment of Indians through such FDI’s.

Class 9 Political Science Chapter 5 India and Other Countries Additional Important Questions and Answers

Choose the correct option from the given options and rewrite the statements:

Question 1.
in l972,______ provided a new format to the interaction between India and Pakistan.
(a) Tashkent Agreement
(b) Shimla Agreement
(c) Civil Nuclear Agreement
(d) Nuclear Non-Proliferation Treaty
Answer:
(b) Shimla Agreement

Question 2.
Aung Sang Su Kyi is credited with having established democracy in ______.
(a) Bhutan
(b) Myanmar
(c) Cambodia
(d) the Maldives
Answer:
(b) Myanmar

Question 3.
The border dispute between India and China is related to ______ area and the Macmahon line.
(a) Sir Creek Area
(b) Siachien
(c) Aksai Chin
(d) Baltistan
Answer:
(c) Aksai Chin

Question 4.
Due to a series of tripartite talks between ____, China and India, Sino-Indian relations are improving slowly.
(a) Pakistan
(b) America
(c) Russia
(d) Japan
Answer:
(b) America

Question 5.
When China was stepping up its military control in Tibet,_____ took asylum in India.
(a) Dalai Lama
(b) Avalokiteshwara
(c) Bodhisattvas
(d) Vajarayana followers
Answer:
(a) Dalai Lama

Question 6.
The ______ signed in 2005 that was approved by the U.S. Congress in 2008 was an important landmark in Indo-American relations.
(a) Comprehensive Test Ban Treaty
(b) Nuclear Non-Proliferation Treaty
(c) Civil Nuclear Agreement
(d) Treaty of Friendship and Co-operation
Answer:
(c) Civil Nuclear Agreement

Question 7.
The policy of increasing trade with South-East Asian nations is known as the ______ policy.
(a) Act East
(b) Pact East
(c) Look East
(d) Seek East
Answer:
(c) Look East

Question 8.
The Summit Conference of India and Africa was held in 2015 with representatives from all _____ African nations attending it.
(a) 54
(b) 56
(c) 58
(d) 53
Answer:
(a) 54

Question 9.
India has co-operated in the project to produced ______ on a large scale, using the water source in Bhutan.
(a) Irrigation facilities
(b) Hydel power
(c) Tube wells
(d) Water reservoirs
Answer:
(b) Hydel power

Question 10.
_______has agreed to extend cooperation and technological help to India in the development and security of coastal areas.
(a) Malaysia
(b) Indonesia
(c) Brunei
(d) Japan
Answer:
(d) Japan

Question 11.
European Nations, especially ______ invest on a large scale in the field of technology in India.
(a) Greece and Italy
(b) Germany and France
(c) Belgium and Netherlands
(d) Spain and Portugal
Answer:
(b) Germany and France

Question 12.
The dominance of the terrorist organisation _______ is responsible for political instability in Afghanistan.
(a) Lashkar-e-Taiba
(b) Jamaat-ud-Dawa
(c) Taliban
(d) Al-Qaeda
Answer:
(c) Taliban

State whether the following statements are true or false with reasons:

Question 1.
Write about India’s relation with Maldives.
Answer:
(i) India’s relations with Maldives have been friendly right from the beginning. This small nation to the South of India is dependent on India for a lot of reasons.

(ii) Trade relations have been established between the two since 1981.

(iii) India has helped Maldives in the development of basic facilities or infrastructure, health and communication.

(iv) From 2006 onwards, co-operation in the military field also started between the two countries.

(v) They have entered into treaties with respect to cooperation in space research, conservation of historical objects and tourism. Similarly, they have decided to co-operate in the area of fighting against terrorism.

Write short notes:

Question 1.
SAARC
Answer:
(i) SAARC is a regional organisation established by the South Asian countries in 1985.

(ii) The aim of this organisation is to encourage economic co-operation between South Asian nations and there by, achieve the development of the South Asian region.

(iii) The organisation of SAARC is a platform for South Asian countries to come together and discuss common questions and interests.

(iv) Some common interests of South Asian countries are alleviation of poverty, development of agriculture and technological revolution.

(v) Some treaties were signed on the SAARC platform to make it easy for South Asian countries to trade with each other.

Do as directed:

Complete the following charts:

Question 1.

S.No	Column ’A’	Column ’B’
(1)	Joint Naval Exercises	……….
(2)	Oil imports	………..
(3)	Security in the Indian Ocean	……….
(4)	Hydel Power Plant	………….

Answer:

S.No	Column ’A’	Column ’B’
(1)	Joint Naval Exercises	Japan
(2)	Oil imports	United Arab Emirates
(3)	Security in the Indian Ocean	Sri Lanka
(4)	Hydel Power Plant	Bhutan

Question 2.

S.No.	Help extended by India	Beneficiary Nations
(1)	Sent Peacekeeping Force to restore peace	Sri Lanka
(2)	Supplies during 2015 earthquake	Nepal
(3)	Communication facilities, roads, science and technology, schools, health and irrigation projects	Afghanistan
(4)	Helped in the freedom struggle	Bangladesh
(5)	Cooperation in the project to produce Hydel Power	Bhutan

Answer:

S.No.	Help extended by India	Beneficiary Nations
(1)	Sent Peacekeeping Force to restore peace	Sri Lanka
(2)	Supplies during 2015 earthquake	Nepal
(3)	Communication facilities, roads, science and technology, schools, health and irrigation projects	Afghanistan
(4)	Helped in the freedom struggle	Bangladesh
(5)	Cooperation in the project to produce Hydel Power	Bhutan

Prepare the following flow charts:

Question 1.

Answer:

Question 2.

Answer:

Question 3.

Answer:

Answer the following questions in brief.

Question 1.
Illustrate the differences in world views between India and Pakistan.
Answer:
(i) India and Pakistan have totally different world views.

(ii) In line with the Indian world view, India opposed the military alliances of the Cold War and tried to solve the Indo-Pak conflict bilaterally.

(iii) On the other hand, Pakistan tried to maintain relations with the Islamic world and China entered into a military agreement with America.

Question 2.
Describe the Kashmir issue between India and Pakistan.
Answer:
(i) Pakistan considers Kashmir as the biggest hurdle in establishing relations with India.

(ii) The first Indo-Pak war took place in 1965 over Kashmir.

(iii) The Tashkent Agreement was signed in 1966, but nothing much came out of it.

(iv) Even though the 1971 war was about the creation of Bangladesh, it also had the dimension of the Kashmir problem to it.

(v) The Shimla Agreement in 1972 provided a new format to the interaction between India and Pakistan.

(vi) In 1999, there was a conflict between India and Pakistan over the infiltration by Pakistan in the Kargil region.

(vii) Even today, the Kashmir question is the basic cause of conflict between the two countries.

Question 3.
Sino-Pak Friendship has affected the security of India. Explain.
Answer:
(i) The threat to India’s security is increasing due to friendship between China and Pakistan, supply of weapons from China to Pakistan and also transfer of missile and nuclear weapons technology.

(ii) The increasing friendship between China and Pakistan and increasing influence of China over India’s other neighbours is a cause of concern for India.

Question 4.
How is India trying to resolve its differences with China?
Answer:
(i) India has always made efforts to improve relations with China.

(ii) A joint executive group has been set up to solve the Sino-Indian border dispute.

(iii) When the rate of economic growth of both India and China increased, the trade relations between both the countries began to get strengthened.

(iv) Because of improvement in economic and trade relations between India and China and a series of tripartite talks between Russia, China and India, Sino-Indian relations are improving slowly.

(v) Even though the border dispute is not completely resolved, it has taken a back seat and relations in other areas have become more important.

Question 5.
How was Bangladesh created?
Answer:
(i) Today’s Bangladesh is the erstwhile East Pakistan. When Pakistan was created, it had two parts: West and East Pakistan.

(ii) There was linguistic difference between them. There were other political conflicts as well.

(iii) The movement to liberate Bangladesh emerged out of this.

(iv) This movement tried to free Bangladesh from the dominance of West Pakistan.

(v) India helped Bangladesh in its freedom struggle. Bangladesh was formed in 1971.

Question 6.
How could India and African nations benefits from each other?
Answer:
(i) Having close relations with Africa will be beneficial from the point of view of both.

(ii) Many countries in Africa are developing rapidly.

(iii) MaharashtraBoardSoLutions.com diness to help in the all-round development of African youth. India has also agreed to give economic help and even grants to bring about development in different areas like technology, agriculture, tourism, etc.

(iv) India’s energy needs can be fulfilled by the energy rich countries like Egypt, Nigeria, Angola and Sudan.

(v) India is making efforts to increase trade with Africa.

Balbharti Maharashtra State Board Class 9 Science Solutions Chapter 13 Carbon: An Important Element Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 9 Science Solutions Chapter 13 Carbon: An Important Element

Class 9 Science Chapter 13 Carbon: An Important Element Textbook Questions and Answers

1. Select the proper option and complete the statements
(single, all, double, ionic, carbon, give and take, hydrogen, multiple, share, most, covalent)

a. A carbon atom forms a ….……………. bond with other atoms. In this bond the two atoms ….electrons.
Answer:
covalent, share

b. All the carbon bonds in a saturated hydrocarbon ….……………. electrons.
Answer:
share

c. At least one carbon bond in an unsaturated hydrocarbon is ….…………… .
Answer:
multiple

d. ….……………. is the essential element in all the organic compounds.
Answer:
Carbon

e. The element hydrogen is present in ….. organic compound.
Answer:
all

2. Answer the following questions

a. Why are carbon and its compounds used as fuels?

Answer:
(i) The name ‘carbon’ is derived from Latin word ‘carbo’meaning coal. In the earth’s crust, carbon is present to an extent of approximately 0.27% in the form of carbonate, coal and petroleum. One of the non-crystalline and amorphous form of carbon is coal. Coal is a fossil fuel.

(ii) Peat, lignite, bituminous and anthracite are the four types of coal in the increasing order of their carbon content and heat produced respectively. Charcoal and coke are the other amorphous forms of carbon used as fuel.

(iii) Compounds of carbon such as hydrocarbons consist of carbon and hydrogen and they are easily combustible. For example, methane (CH₄) which occurs in natural gas is highly inflammable. It bums by reacting with oxygen to give a bluish flame. In this reaction, 213 Kcal/mol of heat is given out. Methane bums completely.

Chemical reaction:
CH₄ + 2O₂ → CO₂ + 2H₂O + Heat

(iv) Thus when hydrocarbons are burnt in air, large amount of heat is evolved with formation of carbon dioxide (CO₂) and water (H₂O). Due to evolution of heat on combustion, carbon and its compounds are used as fuels.

b. In which compound forms does carbon occur?
Answer:
Carbon in its combined state exists as various compounds such as:

• Carbon dioxide and in the form of carbonates such as calcium carbonate, marble, calamine (ZnCO₃).
• Fossil fuel – coal, petroleum, natural gas.
• Carbonaceous nutrients – carbohydrates, proteins, fats.
• Natural fibres – cotton, wool, silk.
• Hydrocarbons – compound of carbon and hydrogen.

c. Write the uses of the diamond.
Answer:
Uses of diamonds are:

• Diamonds are used in glass cutting and rock drilling machines.
• Diamonds are used in ornaments.
• Diamond knives are used in the eye surgery.
• Diamond dust is used for polishing other diamonds.
• Diamond is used to make windows giving protection from radiation in space and in artificial satellites.

3. Explain the difference:

a. Diamond and graphite.

Answer:

Diamond	Graphite
(i) Diamond is a brilliant, hard and crystalline allotrope of carbon.	(i) Graphite is a black, soft, brittle and slippery crystalline allotrope of carbon.
(ii) In diamonds, every carbon atom is bonded to four neighbouring atoms by covalent bonds forming tetragonal three dimensional structure which makes it very hard.	(ii) In graphite, every carbon atom is bonded to three other carbon atoms by covalent bonds in such a way that a hexagonal layered structure is formed. A graphite crystal is made of many such layers of carbon atoms. These layers slip over each other on applying pressure.
(iii) Density of diamond is 3.5 g/cm3.	(iii) Density of graphite is 1.9 to 2.3 g/cm3.
(iv) Diamond is a bad conductor of electricity as it does not have free electrons.	(iv) Inside each layer of graphite, free electrons move continuously within the entire layer. Hence, graphite is a good conductor of electricity.

b. Crystalline and non-crystalline forms of carbon.
Answer:

Crystalline forms of carbon	Non-crystalline forms of carbon
(i) A crystalline form has a regular and definite arrangement of atoms. (ii) They have high melting points and boiling points. (iii) A crystalline form has a definite geometrical shape, sharp edges and plane surfaces. (iv) Diamond, graphite and fullerene are different crystalline forms of carbon.	(i) A non-crystalline form does not have a regular and definite arrangement of atoms. (ii) They have low melting points and boiling points. (iii) They are amorphous, hence, they do not have definite geometrical shape. (iv) Coal, charcoal and coke are different non­crystalline/amorphous forms of carbon.

4. Write scientific reasons

a. Graphite is a conductor of electricity.
Answer:

• In graphite, each carbon is bonded to three other carbon atoms in such a way that a hexagonal layered structure is formed.
• Due to this structure, graphite has free electrons available.
• These free electrons move continuously within the entire layer.
• Hence, graphite is a good conductor of electricity.

b. Graphite is not used in ornaments.
Answer:

• Graphite is a black, soft, brittle and dull form of carbon.
• It is neither malleable nor ductile.
• These properties of graphite make it unsuitable for making of ornaments.
• Hence, graphite is not used for making ornaments.

c. Limewater turns milky when CO₂ is passed through it.
Answer:

• Limewater traditionally means a weak solution of the alkali calcium hydroxide Ca(OH)₂.
• When CO₂ is passed through limewater, it reacts with calcium hydroxide to form insoluble particulates (precipitate) of Calcium carbonate (CaCO₃).
• Calcium carbonate is weak basic salt and this gives a milky white precipitate.
• Hence, lime water turns milky when CO₂ gas is passed through it.

d. Biogas is an eco-friendly fuel.
Answer:

• Biogas is formed by the decomposition of animal dung, dry leaves, wet garbage in a biogas plant.
• This produces methane gas also called biogas.
• Biogas is a very cheap fuel option which meets the demand for cooking gas.
• Biogas is eco-friendly as it contains about 55% to 60% of methane and rest is carbon dioxide, hence, on combustion it does not produce harmful gases which cause pollution.
• Biogas is a fuel which is convenient to use and in addition to this it produces a very good manure as a side product of the process.
• Hence, biogas is an eco-friendly fuel.

5. Explain the following.

a. Diamond, graphite and fullerenes are crystalline forms of carbon.
Answer:

• Carbon exhibits a property of allotropy in which an element exists in more than one form in nature.
• The chemical properties of these different forms are the same but their physical properties are different.
• Carbon exists in crystalline as well as non-crystalline (amorphous form).
• Crystalline form has a regular and definite arrangement of atoms. They have high melting points and boiling points.
• A crystalline form has a definite geometrical shape, sharp edges and plane surfaces.
• Carbon has three crystalline allotropes such as diamond, graphite and fullerene.
• In the structure of diamond, every carbon atom is bonded to four neighbouring atoms by covalent bonds.
• Therefore, diamond has a tetragonal three dimensional structure which makes it very hard.
• Brilliant and pure diamond is the hardest natural substance.
•  In the structure of graphite, every carbon atom in graphite is bonded to three other carbon atoms in such a way that a hexagonal layered structure is formed.
• A graphite crystal is made of many sheets or layers of carbon atoms.
• These layers slip over each other on applying pressure. One layer of graphite is called graphene.
• Fullerene is rarely found in nature. It is found in soot and in interstellar space.
• The first example of fullerene is Buckminster fullerene (C₆₀).
• This allotrope of carbon is named fullerene after the architect.
• Richard Buckminster Fuller because the structure of C₆₀ resembles the structure of the geodesic dome he designed.
• (xi) Molecules of fullerenes are found in the form of buckyballs and buckytubes.
• (xii) There are 30 to 900 carbon atoms in one molecule of a fullerene. , C₆₀, C₇₀, C₇₆, C₈₂ and C₈₆ are other examples of fullerene. Their molecules occur in small numbers in soot.

b. Methane is called marsh gas.
Answer:

• Methane is formed by the decomposition of plant and animal matter in swamps or marshy areas.
• As methane gas bubbles out from marshy area, it is called as marsh gas.

c. Petrol, diesel, coal are fossil fuels.
Answer:
(i) A fossil fuel is a fuel formed by natural processes, such as anaerobic decomposition of buried dead organisms. Fossil fuels contain high percentage of carbon. The word carbon is derived from the Latin word ‘Carbo’ meaning coal.

(ii) Coal is formed from the remains of trees and other vegetation. Approximately 350 million years ago, these remains were trapped on the bottom of swamps, accumulating layer after layer and creating a dense material called peat. As this peat was buried under more and more ground, the high temperature and pressure transformed it into coal.

(iii) Petrol and diesel are obtained from mineral oil. Mineral oil also called as crude oil or petroleum oil is formed from the remains of plants and animals that lived in the seas millions of years ago. This plant and animal matter has been drawn down and subjected to extremes of temperature and pressure over millions of years ago.

(iv) Mineral oil is commonly formed in rocks under the sea bed. The word petroleum is derived from Latin word ‘Rock oil’. Petrol and Diesel are obtained from mineral oil by the process called as fractional distillation.
Thus petrol, diesel and coal are fossil fuels.

d. Uses of various allotropes of carbon.

e. Use of CO₂ in fire extinguisher.
Answer:

• CO₂ based fire extinguishers do not cause corrosion and are non-conductors of electricity.
• It is beyond their capacity to extinguish a big fire.
• Therefore these fire extinguishers are used to extinguish small scale fire of electrical and electronic equipments.

f. Practical uses of CO₂.
Answer:
Practical uses of CO₂ are:

• CO₂ is used to make aerated drinks.
• CO₂ obtained by chemical reaction or kept under pressure is used in fire extinguishers. Liquified CO₂ is used to remove caffeine from coffee.
• Liquid CO₂ is used as solvent in modem eco-friendly dry cleaning.
• Solid carbon dioxide is used in cold storage and to keep milk and milk products and frozen substances cool during transport. It is also used for getting special effects of a mist in dramas and movies.

6. Write two physical properties each.

a. Diamond
Answer:
Properties of diamond are:

• Brilliant and pure diamond is the hardest natural substance.
• The density of diamond is 3.5 g/cm³.
• The melting point of diamond is 3500 °C.
• When a diamond is heated at 800 °C in the presence of oxygen, CO₂ is given away. In this process no other product besides CO₂ is formed.
• Diamond does not dissolve in any solvent.
• Acids/bases have no effect on diamond.
• Diamond is a bad conductor of electricity as it does not have free electrons.

b. Charcoal
Answer:

• The charcoal that is made from animals is made from their bones, horns, etc.
• On the other hand, the charcoal made from plants is formed by combustion of wood in an insufficient supply of air.

c. Fullerene
Answer:
Properties of fullerenes are:

• Molecules of fullerenes are found in the form of buckyballs and buckytubes.
• There are 30 to 900 carbon atoms in one molecule of a fullerene.
• Fullerenes are soluble in organic solvents such as carbon disulphide, chlorobenzene.

7. Complete the following Chemical reactions.

1. ………………..+………………..→ CO + 2H₂O + Heat
2. ………………..+………………..→ HCl + Cl + HCl
3. 2 NaOH + CO₂ →………………..+………………..
Answer:

8. Write answers to the following in detail.

a. What are the different types of coal? What are their uses?
Answer:
Coal is a fossil fuel. It contains carbon, hydrogen and oxygen. It also contains nitrogen, phosphorus and sulphur. It occurs in the solid state. It is of four types.

• Peat: Formation of peat is the first step in the formation of coal. It contains a high proportion
  of water and less than 60% of carbon. Therefore, not much heat can be obtained from peat.
• Lignite: Peat was transformed into Lignite due to increased pressure and temperature inside the earth. It contains 60 to 70% of carbon.- Lignite is the second step of the formation of coal.
• Bituminous coal: Bituminous coal was formed as the third step of formation of coal. It contains 70 to 90% of carbon.
• Anthracite: Anthracite is known as the pure form of coal. This coal is hard and contains about 95% of carbon.

Uses of coal:

• Coal is used as fuel in factories and homes.
• Coal is used to obtain coke, coal gas and coal tar.
• Coal is used in thermal power plants for generation of electricity.

b. How will you prove experimentally that graphite is good conductor of electricity?
Answer:
Apparatus required: Lead pendi, electrical wires, battery/cell, small bulb, etc.

Step-I: Remove the lead from a pencil and assemble the apparatus as shown in the diagram.

Step-II:

• Start the electric current in the circuit, the moment the electric current is passed through the circuit, the bulb glows.
• This experiment proves that graphite is a good conductor of electricity as graphite has free electrons moving continuously within the entire layer and these free electrons conduct electricity in the lead of the pencil.

c. Explain the properties of carbon.
Answer:
Allotropic nature of Carbon: Some elements occur in nature in more than one form. The chemical properties of these different forms are the same but their physical properties are different. This property of elements is called allotropy. Carbon shows the property of allotropy.

Carbon allotropes are of two types:
(A) Crystalline forms:
Carbon has three crystalline allotropes: Diamond, Graphite and Fullerene. Properties of crystalline forms of carbon are as follows:

• A crystalline form has a regular and definite arrangement of atoms.
• They are made up of only carbon atoms.
• They have high melting points and boiling points.
• A crystalline form has a definite geometrical shape, sharp edges and plane surfaces.

(B) Amorphous forms or non-crystalline forms: Coal, charcoal, coke are the non-crystalline forms of carbon.
Properties of non-crystalline forms of carbon are as follows:

• The arrangement of carbon atoms in this form is not regular.
• Apart from carbon atoms, they also contain hydrogen, oxygen, nitrogen, phosphorus and sulfur atoms.
• Compared to a crystalline form, they have low melting and boiling points.
• Most of them are used as fuels.

d. Classify carbon.
Answer:
Carbon is classified as follows:

9. How will you verify the properties of carbon dioxide?
Answer:
Properties of carbon dioxide can be verified in the following ways:

• When a burning candle is placed in a gas jar of carbon dioxide, it extinguishes indicating that carbon dioxide is a non-combustible gas and does not support combustion.
• When carbon dioxide gas is passed through lime water, it turns lime water milky due to the formation of insoluble calcium carbonate.
• Moist blue litmus turns red in a gas jar of carbon dioxide indicating, it is acidic in nature.
• Carbon dioxide is fairly soluble in water, it dissolves in water forming carbonic acid.

Class 9 Science Chapter 13 Carbon: An Important Element Intext Questions and Answers

Can you recall?

Question 1.
Whatremains behind on complete combustion of any organic compound?
Answer:
A black colour substance ‘Carbon’ remains behind on complete combustion of any organic compound.

Question 2.
What type of element is carbon? Give some information about it.
Answer:

• Carbon is a non-metallic element. It is available ‘ abundantly in the nature and occurs in free as well as combined state.
• Carbon in free state is found as diamond and graphite and in combined state it is present to the extent of approximately 0.27% in the form of carbonate, coal, petroleum.
• In atmosphere, the proportion of carbon in the form of carbon dioxide is approximately 0.03%.

Question 3.
What is an element? What are the different types of elements.
Answer:

• A substance which cannot be decomposed into simple substances by any physical or simple chemical method is called as an Element.
• An element is composed of atoms of only one kind.
• The different types of elements are:
  (a) Metals – Examples: Gold, Silver, etc.
  (b) Non-metals – Examples: Carbon, Sulphur, etc.
  (c) Metalloids – Examples: Silicon, Antimony, etc.

Answer the following questions:

Question 1.
Does an electric charge form on atoms when a covalent bond is formed between them? Why is a single bond between two carbon atoms strong and stable?
Answer:

• No, electric charge is not formed on atoms when a covalent bond is formed between them. This is because covalent bond is formed by sharing of electrons.
• Therefore, there is no change in number of electrons and protons in these atoms and they remain electrically neutral.
• Covalent bonds occur when electrons are shared between two atoms. A single covalent bond is formed when only one pair of electrons is shared between atoms.
• In this sharing, the atomic orbitals directly overlap between the nuclei of two atoms forming the strongest type of covalent bond called as sigma bond.
• Hence, a single covalent bond between two carbon atoms is strong and stable.

Question 2.
In which of the solvents – water, kerosene and cooking oil does the coal powder dissolve?
Answer:
Solvents such as water, kerosene and cooking oil do not dissolve coal powder in them.

Question 3.
What inference will you draw about the solubility of carbon?
Answer:
Carbon is insoluble in water, kerosene and cooking oil.

Question 4.
Is the density of CO₂ more or less than that of air?
Answer:

1. Density is defined as mass per unit volume of a substance, expressed as kilograms per cubic meter.
2. At standard temperature and pressure, the density of air is 1.29 kg/m³. While that of carbon dioxide (CO₂) is 1.79 kg/m³. Hence, density of CO₂ is more than that of air.

Question 5.
What is a compound? How are compounds formed?
Answer:

• A compound is a substance formed when two or more elements are chemically bonded with each other in definite proportion by weight.
• When atoms or two or more different elements chemically react with each other in a definite proportion by weight, a compound is formed.
• The properties of a compound are altogether different from its constituent elements.
• Example: Pure water is a compound made up of two elements Hydrogen and Oxygen. Hydrogen (H) atoms and oxygen (O) atoms have chemically reacted with each other in definite proportion to form a compound-water (H₂O). The proportion of hydrogen and oxygen in water by volume is 2 : 1 and by weight is 1 :8 respectively.
• The properties of water are altogether different from the properties of its constituent elements, hydrogen and oxygen.

Class 9 Science Chapter 13 Carbon: An Important Element Additional Important Questions and Answers

Choose and write the correct option:

Question 1.
The organic compound having double or triple bond in them is termed as
(a) unsaturated
(b) inorganic
(c) saturated
(d) complete
Answer:
(a) Unsaturated hydrocarbon

Question 2.
Covalent compounds are generally soluble in solvents.
(a) inorganic
(b) organic
(c) mixed
(d) mineral
Answer:
(b) organic

Question 3.
Methane is also called as
(a) maha gas
(b) mar’s gas
(c) Anthracite
(d) marsh gas
Answer:
(d) Marsh gas

Question 4.
is an alio trope of carbon used to make ornaments.
Answer:
Diamond

Question 5.
The number of valence electrons in carbon is
(a) 4
(b) 5
(c) 6
(d) 3
Answer:
(a) 4

Question 6.
In saturated hydrocarbons, two carbon atoms are linked by
(a) double bond
(b) triple bond
(c) multiple bond
(d) single bond
Answer:
(d) single bond

Question 7.
Carbon has 4 valence electrons in its outermost shell, hence, it is
(a) divalent
(b) tetravalent
(c) trivalent
(d) pentavalent
Answer:
(b) tetravalent

Question 8.
Methanogenic bacteria act on the organic acids to produce
(a) oxygen gas
(b) nitrogen gas
(c) methane gas
(d) carbon dioxide gas
Answer:
(c) Methane gas

Question 9.
is used to remove caffeine from coffee.
(a) liquefied O₂
(b) liquefied N₂
(c) liquefied CO₂
(d) liquefied CH₄
Answer:
(c) Liquified CO₂

Question 10.
Exhaled air contains about CO₂.
(a) 4%
(b) 3%
(c) 5%
(d) 6%
Answer:
(a) 4%

Question 11.
Electronic configuration of carbon is
(a) (2, 2)
(b) (2,4)
(c) (2, 5,4)
(d) (2, 6)
Answer:
(b) 2, 4

Question 12.
Molecular formula of ethane is
(a) C₃H₄
(b) C₂H₄
(c) C₂H₆
(d) C₂H₂
Answer:
(c) C₂H₆

Question 13.
Molecular mass of carbon dioxide is
(a) 28
(b) 22
(c) 56
(d) 44
Answer:
(d) 44

Question 14.
On heating a mixture of hydrogen and carbon monoxide gases at 300°C in the presence of nickel (catalyst) is formed.
(a) carbon dioxide gas
(b) oxygen gas
(c) methane gas
(d) ethylene gas
Answer:
(c) methane gas

Question 15.
Ethane with molecular formula C₂H₆ has covalent bonds.
(a) six
(b) seven
(c) eight
(d) nine
Answer:
(b) seven

Question 15.
Weight of Kohinoor Diamond was
(a) 186 carats
(b) 27 carats
(c) 252 carats
(d) 23 carats
Answer:
(a) 186 carats

Question 16.
Covalent compounds have
(a) high melting point
(b) low melting point
(c) moderate melting point
(d) very high melting point
Answer:
(b) low melting point

Question 17.
Methane is
(a) C₂H₆
(b) C₃H₈
(C) CH₂
(d) CH₄
Answer:
(d) CH₄

Question 18.
Wohler, a German scientist synthesized the compound from an inorganic compound ammonium cyanate.
(a) methane
(b) ethylene
(c) urea
(d) acetic acid
Answer:
(c) urea

Question 19.
Molecular mass of methane is
(a) 19
(b) 16
(c) 17
(d) 18
Answer:
(b) 16

Question 20.
coal contains highest percentage of carbon.
(a) Bituminous
(b) Peat
(c) Anthracite
(d) Lignite
Answer:
(c) Anthracite

Question 21.
H₂C = CH₂ is ……………………… .
(a) Propane
(b) Ethyne
(c) Ethane
(d) Ethene
Answer:
(d) Ethene

Question 22.
CH₃ – C = CH is ……………………… .
(a) Propene
(b) Propyne
(c) Ethyne
(d) Ethene
Answer:
(b) Propyne

Question 23.
Carbon dioxide gas is not used in
(a) photosynthesis
(b) aerated drinks
(c) glass cutting
(d) fire extinguishers
Answer:
(c) glass cutting

Question 24.
Melting point of diamond is
(a) 3700 °C
(b) 3500 °C
(c) 4000 °C
(d) 2500 °C
Answer:
(b) 3500 °C

Question 25.
Melting point of C02 is
(a) 26 °C
(b) 56 °C
(c)-56.6°C
(d)-98°C
Answer:
(c) -56.6 °C

Question 26.
Melting point o* methane is
(a) -182.5 °C
(b) -161.5 °C
(c) 182.5 °C
(d) 161.5 °C
Answer:
(a) -182.5 °C

Question 27.
Biogas contains about methane.
(a) 55% to 60%
(b) 20% to 25%
(c) 90% to 95%
(d) 40% to 45%
Answer:
(a) 55% to 60%

Question 28.
is not a property of carbon dioxide gas.
(a) Supporting combustion
(b) Odourless
(c) Colourless
(d) Turns blue litmus red
Answer:
(a) Supporting combustion

Name the following:

Question 1.
Industries that use methane in the form of natural gas.
Answer:
Fabric mills, paper mills, food processing industry, petrol purification.

Question 2.
Organic compounds prepared from methane.
Answer:
Ethanol, methyl chloride, methylene chloride, acetylene.

Question 3.
Chemicals used in regular fire extinguisher.
Answer:
Sodium bicarbonate and dilute sulphuric acid.

Question 4.
Components of biogas
Answer:
Methane, carbon dioxide

Question 5.
Organic solvents is which fullerenes are soluble.
Answer:
Carbon disulfide, chlorobenzene.

Question 6.
Use of carbon dioxide is dramas and movies
Answer:
The special effect of mist.

Match the columns:

Question 1.

Column ‘A’	Column ‘B’
(1) Diamond (2) Fullerenes (3) Graphite	(a) Hexagonal layered structure (b) Tetragonal three-dimensional structure (c) Geodesic dome

Answer:
(1-b),
(2- c),
(3 – a)

Question 2.

Column ‘A’	Column ‘B’
(1) Peat (2) Lignite (3) Bituminous (4) Anthracite	(a) 60-70% of Carbon (b) 95% of Carbon (c) less than 60% of Carbon (d) 70 – 90% of Carbon

Answer:
(1 – c),
(2 – a),
(3 – d),
(4 – b)

Question 3.

Column ‘A’	Column ‘B’
(1) Propyne (2) Propene (3) Propane	(a) CH3 – CH2 – CH3 (b) CH3 – C = CH (c) CH3 – CH = CH2

Answer:
(1 – b),
(2 – c),
(3 – a)

Question 4.

Column ‘A’	Column ‘B’
(1) Fullerene (2) Diamond (3) Graphite	(a) Lubricants (b) Insulator (c) Ornaments

Answer:
(1 – b),
(2 – c),
(3 – a)

Question 5.

Column ‘A	Column ‘B’
(1) Water gas (2) Methane gas (3) Producer gas (4) Carbon dioxide gas	(a) CH4 (b) CO + H2 (c) CO2 (d) CO + H2 + CO2 + N2

Answer:
(1 – b),
(2 – a),
(3 – d),
(4 – c)

State whether the following statements are true or false. Correct the false statement.

(1) Study of organic compounds is called as organic chemistry.
(2) Hydrocarbons with double bonds are called as saturated hydrocarbons.
(3) Ethene is saturated hydrocarbon.
(4) Covalent compounds are good conductor of electricity.
(5) Methane is a covalent compound.
(6) Covalent compounds are soluble in organic solvents.
(7) Graphite is used in making lubricants and lead pencils.
(8) The density of diamond is 9.8 g/cm³.
(9) Diamond knives are used in eye surgery.
(10) Fullerenes are used as insulators.
(11) Coke is used in production of water gas i.e. (CO₂ + H₂O).
(12) Structural formula of propyne is CH₃ – C = CH.
(13) COz is used to make aerated drinks.
(14) Methane gas is black in colour.
(15) Production of biogas is aerobic process.
Answer:
(1) True
(2) False. Hydrocarbons with double bonds are called as Unsaturated hydrocarbons.
(3) False. Ethene is Unsaturated hydrocarbon.
(4) False. Covalent compounds are bad conductor of electricity.
(5) True
(6) True
(7) True
(8) False: The density of diamond is 3.5 g/cm³.
(9) True
(10) True
(11) False. Coke is used in production of water gas i.e. (CO + H₂).
(12) False. Structural formula of propyne is CH₃ – C = CH.
(13) True
(14) False. Methane gas is colourless.
(15) False. Production of biogas is anaerobic process.

Find the odd man out:

Question 1.
Propane, Methane, Ethene, Pentane.
Answer:
Ethene. It is an unsaturated hydrocarbon with double bond between two carbon atoms while rest are saturated hydrocarbons with single bond between two carbon atoms.

Question 2.
CH₄, C₂H₆, C₃H₈, CaCO₃.
Answer:
CaCO₃. It is a salt which is an inorganic’ compound, while rest are hydrocarbon compounds, i.e. organic compounds.

Question 3.
C₂H₂, C₃H₈, C₂H₆, CH₄.
Answer:
C₂H₂. It is an unsaturated hydrocarbon with triple bonds while rest are saturated hydrocarbons with single bonds between two carbon atoms.

Question 4.
Diamond, Fullerene, Graphite, Methane.
Answer:
Methane. It is a marsh gas while rest are allotropes of carbon.

Question 5.
Coal, Petroleum, Natural gas, Cotton
Answer:
Cotton. Cotton is a natural fibre while rest all are fossil fuels.

Question 6.
Cotton, Silk, Proteins, Wool
Answer:
Proteins. Proteins are carbonaceous nutrients while rest all are natural fibres.

Question 7.
Carbohydrates, Coal, Proteins, Fats
Answer:
Coal. Coal is a fossil fuel while rest all are carbonaceous nutrients.

Question 8.
Peat, Charcoal, Lignite, Bituminous
Answer:
Charcoal. Charcoal is a non-crystalline form of carbon while rest all are types of coal.

Question 9.
Lubricants, Electrodes, Ornaments, Arc Lamps
Answer:
Ornaments. Ornaments are made from diamonds while rest all are made from graphite.

Write the correlated terms:

(1) Propene : Double bond :: Propyne : ……………………. .
(2) Ethane : CH₃ – CH₃ :: Ethene : ……………………. .
(3) Hydrogen : Monovalent :: Carbon : ……………………. .
(4) Methane : Low melting point i.e. -182.5°C Diamond : ……………………. .
(5) Graphite : Hexagonal structure :: Diamond : ……………………. .
(6) Density of Diamond : 3.5 g/cm³ :: Density of Graphite : ……………………. .
(7) Peat: 60% of carbon :: Anthracite : ……………………. .
(8) Melting point of CO₂: -56.6°C :: Melting point of CH₄: ……………………. .
Answer:
(1) Triple Bond
(2) CH₂ = CH₂
(3) Tetravalent
(4) High melting point i.e. 3500°C
(5) Tetragonal structure
(6) 1.9 to 2.3 g/cm³
(7) 95% of carbon
(8) -182.5 °C

Give scientific reasons:

Question 1.
Covalent compounds have low melting and boiling points.
Answer:

• When substances melt or boil, bonds between the molecules are broken due to heat supplied.
• On covalent compounds, the intermolecular forces of attraction are weak.
• Hence, intermolecular forces in covalent compounds are broken easily due to which they have low melting and boiling points.

Question 2.
Graphite is a good conductor of electricity whereas diamond is a non-conductor of electricity.
Answer:

• In diamond, each carbon atom uses all its four electronic to get bonded to another carbon atom, whereas in graphite each carbon uses there out of four electrons during bonding.
• Hence in diamond no free electrons are left whereas in graphite free electrons are available.
• Due to the presence of electron which are free to flow graphite is a good conductor of electricity, whereas due to the absence of free electrons diamond is a non-conductor of electricity.

Question 3.
Graphite is used as a lubricant.
Answer:

• Lubricants are used to reduce friction and wear and tear of mechanical parts.
• Graphite is smooth and slippery and hence is useful in reducing friction. Hence, graphite is used as a lubricant.

Question 4.
Methane is used as a domestic fuel.
Answer:

• Methane is highly inflammable.
• It burns by reacting with oxygen to give a bluish flame.
• It burns completely and producers 213 Kcal/ mol of heat.
• Being the smallest hydrocarbon, the proportion of CO2 released in the combustion of methane is small.
• Therefore methane is used as a domestic fuel.

Answer in short:

Question 1.
What was the contribution of chemist Wohier in organic chemistry?
Answer:

• The German chemist Wohier synthesized an organic compound urca from an inorganic compound ammonium cyanate,
• Ever since then, many organic compounds have been made from inorganic compounds.
• Carbon was found to he the main element in all these compounds.
• Hence, organic chemistry is also referred to as chem is try of carbon corn pounds.

Question 2.
With neat diagram explain the structure of diamond.
Ans.

• In diamond, every carbon atom is bonded to four neighbouring atoms by covalent bonds.
• Therefore, diamond has a tetragonal three dimensional structure which makes it very hard.
  

Question 3.
With neat diagram explain the structure of graphite?
Answer:

• Every carbon atom in graphite is bonded to three other carbon atoms in such a way that a hexagonal layered structure is formed.
• A graphite crystal is made of many sheets or layers of carbon atoms.
• These layers slip over each other on applying pressure.
• One layer of graphite is called graphene.
  

Question 4.
Give the properties of graphite.
Answer:
Properties of graphite are:

• Graphite found in nature is black, soft, brittle and slippery.
• Inside each layer of graphite, free electrons move continuously within the entire layer. That is why graphite is a good conductor of electricity.
• Due to the layered structure graphite can be used for writing on paper.
• The density of graphite is 1.9 to 2.3 g/cm3.
• Graphite does not dissolve in most solvents.

Question 5.
Give the uses of graphite.
Answer:
Uses of graphite are:

• Graphite is used for making lubricants.
• Graphite is used for making carbon electrodes.
• Graphite is used in pencils for writing.
• Graphite is used in paints and polish.
• Graphite is used in arc lamps which gives a very bright light.

Question 6.
Give the uses of fullerenes.
Answer:
Uses of Fullerenes are:

• Fullerenes are used as insulators.
• Fullerenes are used as a catalyst in water purification.
• At a certain temperature, fullerene exhibits superconductivity.

Question 7.
What is Coal?
Answer:

• Coal is a fossil fuel. It contains carbon, hydrogen and oxygen.
• It also contains nitrogen, phosphorus and sulphur.
• It occurs in the solid state. It is of four types – peat, lignite, bituminous and anthracite.

Question 8.
What is Coke?
Answer:
The pure coal that remains when coal gas has been taken away from coal, is called coke.

Question 9.
Give the uses of Coal.
Answer:
Uses of Coal are:

• Coal is used as fuel in factories and homes.
• Coal is used to obtain coke, coal gas and coal tar.
• Coal is used in thermal power plants for generation of electricity.

Question 10.
Give the uses of Coke.
Answer:
Uses of Coke are:

• Used as domestic fuel.
• Coke is used as a reducing agent.
• Coke is used in production of water gas (CO + H₂) and producer gas (CO + H₂ + CO₂ + N₂)

Question 11.
Name the types of coal and give the differences in them.
Answer:
The four types of coal are Peat, Lignite, Bituminous and Anthracite.

Question 12.
Give the properties of covalent compounds.
Answer:
Properties of covalent compounds:

• Covalent compounds have low melting points and boiling points.
• Generally they are insoluble in water and soluble in organic solvents.
• They are poor conductors of heat and electricity.

Question 13.
What are saturated hydrocarbons? Give examples.
Answer:

• The hydrocarbons having only single bonds between carbon atoms are called saturated hydrocarbons.
• For example, ethane (C₂H₆) which is (CH₃ – CH₃), propane (C₃H₈) which is (CH₃ – CH₂ – CH₃).

Question 14.
What are unsaturated hydrocarbons? Give examples.
Answer:

• Some hydrocarbons have a multiple bond between two carbon atoms.
• A multiple bond can be a double bond or a triple bond.
• Hydrocarbons having at least one multiple bond are called unsaturated hydrocarbons.
• For example, ethene (H₂C = CH₂), ethyne (HC = CH), propene (CH₃ – CH = CH₂), propyne (CH₃ – C = CH).

Question 15.
Give the following information of carbon dioxide: Molecular formula, Molecular mass, Melting point, Percentage occurrence in air.
Answer:
Molecular formula – CO₂, Molecular mass – 44, Melting point -56.6 °C Percentage occurrence in air – 0.03%.

Question 16.
Give the physical and chemical properties of carbon dioxide.
Answer:
Physical properties of carbon dioxide are:

• It is an odourless gas.
• It is a colourless gas.

Chemical properties of carbon dioxide are:

• It is non-combustible and does not support combustion.
• It turns lime water milky.
• It is fairly soluble in water and dissolves in water forming carbonic acid.
• It turns blue litmus red indicating it is acidic in nature.
• The colour of universal indicator turns orange/ yellow in C02 indicating its pH value between 4 and 6, i.e. acidic in nature.

Question 17.
Give the uses of Carbon dioxide.
Answer:
Uses of Carbon dioxide are:

• CO₂ is used to make aerated drinks
• Solid carbon dioxide is used in cold storage and also to keep milk and milk products and frozen substances cool during transport. It is also used for getting special effects of a mist in dramas and movies.
• CO₂ obtained by chemical reaction or kept under pressure is used in fire extinguishers.
• Liquified CO₂ is used to remove caffeine from coffee.
• Liquid CO₂ is used as solvent in modern eco-friendly dry cleaning.
• Plants use CO₂ in air for photosynthesis.

Question 18.
Give the occurrence of methane.
Answer:
The occurrence of methane is as follows:

• Methane occurs in natural gas to the extent of 87%.
• Decomposition of organic matter in the absence of air (anaerobic) produces methane.
• Methane is present in biogas.
• Methane is found in coal mines.
• Methane is found at the surface of marshy places which is why it is also called marsh gas.
• On heating a mixture of hydrogen and carbon monoxide gases at 300 °C in the presence of nickel (catalyst), methane gas is formed.
• Fractional distillation of natural gas gives methane in pure form.

Question 19.
Give the physical properties of methane.
Answer:
Physical properties of methane are:

• Melting point of methane is (-182.5 °C).
• Boiling point of methane is (-161.5 °C).
• It is a colourless gas.
• The density of liquid methane is less than that of water.
• Methane is sparingly soluble in water. It is highly soluble in organic solvents like gasoline, ether and alcohol.
• Methane is in gaseous state at room temperature.

Question 20.
Give the uses of methane.
Answer:
Uses of methane are:

• Methane in the form of natural gas is used in industries such as fabric mills, paper mills, food processing industry, petrol purification.
• Being the smallest hydrocarbon, the proportion of CO₂ released in the combustion of methane is small and, therefore, it is used as a domestic fuel.
• Methane is used for production of organic compounds such as ethanol, methyl chloride, methylene chloride and acetylene.

Question 21.
How is methane formed? Give structural formula and electron dot model of methane.
Answer:

• Atomic number of carbon is 6. The electronic configuration of carbon is (2, 4). The valency of carbon is 4.
• Carbon atom can form four covalent bonds with other carbon atoms or atoms of different elements.
• When a carbon atom shares one electron each with four hydrogen atoms and forms four C-H bonds, a methane (CH₄) molecule is formed.
  

Question 22.
What are organic and inorganic compounds?
Answer:
Compounds obtained directly or indirectly from plants and animals are called organic compounds and compounds obtained from minerals are called inorganic compounds.

Question 23.
What is allotropy?
Answer:

• Allotropy – Some elements occur in nature in more than one form.
• The chemical properties of these different forms are the same but their physical properties are different.
• This property of elements is called allotropy.

Question 24.
What are basic organic compounds? What are they also called as?
Answer:

• The compounds formed from only carbon and hydrogen are called basic organic compounds.
• These are also called hydrocarbons.

Write a balanced chemical equation and explain the following chemical reactions.

Question 1.
Preparation of urea from Ammonium cyanate:
Answer:

Organic compound Urea can be synthesized from an inorganic compound Ammonium cyanate.

Question 2.
Coal when burnt in air
Answer:

When coal is burnt in air, the carbon present in coal combines with oxygen present in air to form carbon dioxide gas.

Question 3.
Calcium carbonate reacts with dilute hydrochloric acid:
Answer:

When Calcium carbonate reacts with dilute hydrochloric add it forms Caldum chloride, water and Carbon dioxide gas is evolved.

Question 4.
Carbon dioxide is passed through an aqueous solution of Sodium hydroxide:
Answer:

When Carbon dioxide gas is passed through an aqueous solution of Sodium hydroxide it forms Sodium carbonate and Water.

Question 5.
Carbon dioxide is passed through an aqueous solution of Sodium carbonate:
Answer:

When carbon dioxide is passed through an aqueous solution of Sodium carbonate, it forms Sodium bicarbonate.

Question 6.
Carbon dioxide is passed through freshly prepared lime water for a short duration and then for longer duration:
Answer:

When Carbon dioxide is passed through freshly prepared lime water, it forms water and white precipitate of Calcium carbonate because of which lime water turns milky.

When Carbon dioxide is continuously passed through milky lime water, it forms Calcium bicarbonate which is soluble in water and therefore, water once again turns colourless.

Question 7.
Carbon dioxide gas is dissolved in water.
Answer:

Carboh dioxide gas is fairly soluble in water, it dissolves in water under pressure to form Carbonic acid.

Question 8.
Sodium bicarbonate reacts with dilute Sulphuric acid, (reaction in fire extinguisher):
Answer:

When Sodium bicarbonate reacts with dilute Sulphuric acid it forms Sodium sulphate, water and Carbon dioxide gas.

Question 9.
Methane gas is burnt in air:
Answer:

Methane is highly inflammable, it burns in air with a bluish flame and combines with oxygen present in air to form Carbon dioxide and water. In these reaction 213 kcal/mol of heat is given out.

Question 10.
Methane and Chlorine gases react with each other.
Answer:

Methane and chlorine gases react with each other at the temperature of 250 °C to 400 °C in presence of ultra voilet light and form mainly Methyl chloride (Chloromethane and ‘ Hydrogen chloride)
This reaction is called Chlorination of methane.

Question 11.
Production of methane gas in biogas plant.
Answer:

In biogas plant, microbes act on the bio-degradable complex organic compounds and produce organic acids.

The methanogenic bacteria act on the organic acids to produce Methane gas and Carbon dioxide gas.

Question 12.
Production of water gas:
Answer:

When super heated steam is passed over red hot coke at high temperature, it forms carbon monoxide gas and hydrogen gas.

This gaseous product of carbon monoxide gas and hydrogen gas together is called as water gas.

With the help of ne abelled diagram explain the following:

Question 1.
Regular fire extinguisher.
Answer:

• A fire extinguisher contains Sodium bicarbonate powder. There is also dilute sulphuric acid placed in a glass capsule.
• On pressing the knob, the capsule breaks and sulphuric acid comes in contact with the sodium bicarbonate. These two react chemically to release CO₂ which comes out.
• CO₂ based fire extinguishers do not cause corrosion and are non-conductors of electricity. Therefore, they are used when electrical or electronic equipment catches fire.
• CO₂ based fire extinguishers are used to extinguish small scale fire. It is beyond their capacity to extinguish a big fire.
• In modern fire extinguishers liquid and solid CO₂ is filled under pressure. On reducing the pressure, it becomes gaseous and comes out forcefully through the horn-like hose pipe.
• Chemical reaction:
  

Question 2.
Biogas plant.
Answer:

• Animal dung, dry leaves, wet garbage get decomposed by anaerobic microbes in a biogas plant.
• This produces methane gas, also called biogas.
• Biogas is a very cheap fuel option which meets the demand for cooking gas. It is also used for the production of electricity.
• Biogas contains about 55% to 60% methane and the rest is carbon dioxide.
• Biogas is a fuel which is convenient to use and, in addition to this, a very good manure is also produced as a side product of the process.
• Biogas production process – Production of biogas is an anaerobic process. It takes place in two stages.
  (a) Production of acids – The microbes act on the biodegradable complex organic compound and produce organic acids.
  (b) Methane gas production – The methanogenic bacteria act on the organic acids to produce methane gas.

Chemical reaction:

Answer the following

Question 1.
What happens when substances like milk, sugar, wool, dry leaves, hair and seeds are heated strongly in hard glass test tube?Answer:
When milk, sugar, wool, dry leaves, hair and seeds are heated strongly in hard glass test tube, they get charred and a black substance is left behind. This black substance is carbon.

Answer the following questions:

Question 1.
Take some milk in an evaporating dish. Heat the evaporating dish on a bunsen burner. What remains behind at the bottom of an evaporating dish on complete evaporation of the milk?
Answer:

• On complete evaporation of milk, a black residue is left behind.
• This residue is of carbon.

Question 2.
Take small samples of sugar, wool, dry leaves, hair, seeds, split pulses and plastic in separate test tubes. Heat each test tube and observe the changes taking place in the substances. What does the black substance in each test tube indicate?
Answer:

• On heating the above samples, they get charred and a black substance is left behind.
• The black substance is carbon.

Question 3.
Apparatus : Coal, match box, moist litmus paper, etc.

Procedure : Ignite the coal. Hold the moist blue litmus paper over the gas released on igniting the coal. Note the observation.

(a) With which gas in the air does the coal react on igniting?
Answer:
Coal reacts with oxygen gas present in the air, on igniting.

(b) What is the substance formed?
Answer:
The substance formed is carbon dioxide.

(c) What change takes place in the litmus paper?
Answer:
The moist blue litmus paper turns red.

(d) Write down the chemical reaction taking place in the above procedure.
Answer:
(i) Carbon combines with oxygen to form Carbon dioxide gas.

(ii) This C02 combines with water present on moist blue litmus paper to form Carbonic acid which turns blue litmus to red.

Question 4.
Apparatus : Pencil, electrical wires, battery/ cell, small bulb, water, kerosene, test tube, lead pencils, etc.

Procedure : Remove the lead from a pencil and arrange the apparatus as shown in the above diagram. Note your observations for the following.

(a) What is the colour of lead in the pencil? .
Answer:
The colour of the lead in the pencil is black as it is made from graphite which is an allotrophic form of carbon.

(b) Try to break lead with your hand.
Answer:
The lead breaks easily as it is made up of graphite which is brittle in nature.

(c) Start the electric current in the circuit and observe. What did you find?
Answer:
When we start the electric current in the circuit, the bulb in the circuit glows, indicating that the lead in the pencil is a good conductor of electricity.

(d) Take some water in a test tube. Take some kerosene in another test tube. Put lead dust in both the test tube. What did you observe?
Answer:
(i) Lead dust does not dissolve in water nor in kerosene.
(ii) It remains insoluble in both the test tubes.

Question 5.
Apparatus : Test tube, straw, lime water, etc.

Procedure: Take freshly prepared lime water in a test tube. Blow air in it for some time through the straw and observe the lime water. Note the observation.

(a) What did you see?
Answer:
When we blow air through the straw in freshly prepared lime water, it turns milky.

(b) What might be the reason behind the change?
Answer:

Freshly prepared lime water is obtained by dissolving lime (CaO) in water (H₂O).

When we blow air through the straw in lime water, carbon dioxide (CO₂) present in the air reacts with lime water to form white precipitate (insoluble substance) of Calcium Carbonate (CaCO₃) due to which lime water turns milky.

Question 6.
With the help of a neat labelled diagram explain the laboratory preparation of Carbon dioxide gas.
Answer:
The laboratory preparation of Carbon dioxide gas is as follows:

Apparatus : Retort stand, round bottom flask, thistle funnel, gas delivery tube, gas jars.
Chemicals : Calcium carbonate (Pieces of Shahabad tiles/marble pieces/limestone), dilute hydrochloric acid.

Procedure:

• Assemble the apparatus as shown in the figure. While assembling, place CaCO₃ in the round bottom flask.
• Add dilute HCl in the flask through thistle funnel. See to it that the end of the funnel dips in the acid.
• CO₂ is formed as a result of the reaction between CaCO₃ and HCl. Collect this gas in four to five gas jars. The chemical equation of the above reaction is as follows. CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂ ↑
  

 

Balbharti Maharashtra State Board Class 9 Political Science Solutions Chapter 4 The United Nations Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 9 Political Science Solutions Chapter 4 The United Nations

Class 9 Political Science Chapter 4 The United Nations Textbook Questions and Answers

1. Choose the right option and rewrite the sentence:

Question 1.
This country is not a permanent member of United Nations Security Council _____.
(a) America
(b) Russia
(c) Germany
(d) China
Answer:
(c) Germany

Question 2.
The United Nations has _______ number of members.
(a) 190
(b) 193
(c) 198
(d) 199
Answer:
(b) 193

Question 3.
This international organisation conducts workshops in India on remedial measures to tackle the problem of malnutrition among children
(a) UNICEF
(b) UNESCO
(c) Trusteeship Council
(d) Red Cross
Answer:
(a) UNICEF

2. Explain with reasons whether the following statements are true or false:

Question 1.
The United Nations General Assembly is a platform to discuss global problems.
Answer:
True.

• Every year the General Assembly meets in its session. During the session, the General Assembly discusses important issues like environment, disarmament, etc.
• The significance of the General Assembly lies in it being a platform for representatives of member nations to come together and discuss and make policy decisions on issues of global importance.

Question 2.
The status of all the member nations of the United Nations is not equal.
Answer:
False.

• As mentioned in the principles of UN, all member nations have the same status.
• There is no discrimination among nations based on geographical size, economic or military power.

Question 3.
A resolution can be passed even if China exercises its veto power.
Answer:
False

• China is one of the five permanent members of the UN and the permanent members have veto power.
• If even one of the five permanent members uses it’s veto i.e. gives a negative vote, the decision cannot be taken.

Question 4.
India has played a major role in the work of the United Nations.
Answer:
True.

• India has always sent her troops to participate in the United Nations peacekeeping forces.
• India has participated in bringing issues like decolonisation, disarmament, racial segregation on the United Nations platform.

3. Explain the following concepts:

Question 1.
Veto
Answer:
(i) Security Council has 5 permanent members and 10 non-permanent members.
(ii) For any decision to be taken, the assent of all five permanent members and four non¬permanent members is necessary.
(iii) America, Russia, England, France and China are permanent members of the Security Council. They have the veto power.
(iv) If even one of the five permanent member uses its veto i.e. gives a negative vote, the decision cannot be taken

Question 2.
UNICEF
Answer:
(i) UNICEF is an affiliated organisation of the United Nations.
(ii) It works towards making nutritious food and health care available to children.
(iii) Several workshops were organised in India to find out measures to overcome malnutrition among babies and children.

4. Answer the following questions in brief:

Question 1.
Write the reasons for the establishment of the United Nations.
Answer:
The United Nations is the world’s largest international organisation. The reasons for the establishment of the United Nations are:

(i) Two World Wars were fought at the beginning of the twentieth century.

(ii) Life and property were destroyed on a large scale in these wars.

(iii) As a result, the League of Nations was established after the First World War and the United Nations was established after the Second World War out of a realisation that there has to be a mechanism to establish world peace.

(iv) The League of Nations did not succeed at all.

(v) But after the use of the nuclear weapons in the . Second World War, the idea took root that such destructive wars should be stopped and that it is the collective responsibility of all nations to do so.

(vi) The United Nations was established after the Second World War to instill this understanding among all nations.

(vii) Hence, the United Nations, an international organisation was established to ensure peace and security at the international level.

Question 2.
Write the objectives of the United Nations.
Answer:
The United Nations has its own definite objectives. They are as follows:

• To establish friendly relations among nations.
• To enhance international security by solving international disputes.
• To safeguard and foster human rights and freedom.
• Along with these, the United Nations also aim at enhancing economic cooperation at the international level.

Question 3.
What is the role of the Peacekeeping Forces of the United Nations?
Answer:
(i) The peacekeeping activity of the United Nations involves creating appropriate circumstances favourable for bringing about permanent peace in strife-tom areas.
(ii) The peacekeeping forces help these areas to progress towards peace.
(iii) In conflict ridden areas, security is provided and at the same time, help is extended for establishing peace.
(iv) The United Nations takes up peacekeeping as one of the tasks for safeguarding and fostering peace in the world.

5. Do as directed:

Question 1.
Complete the following chart giving information about the organs of the United Nations.

S.No	Organ	Number of members	Functions
1.	United Nations General Assembly	……….	…………….
2.	United Nations Security Council	…………..	…………….
3.	International Court of Justice	…………..	……………….
4.	Economic and Social Council	…………..	………………..

Answer:

S.No.	Organ	Number of members	Functions
(1)	United Nations General Assembly	193	(1) To elect the non-permanent members of the Security Council. (2)  To choose the United Nations Secretary General and the judges of the International Court of Justice (ICJ) in consultation with the Security Council. (3) To pass the annual budget of the United Nations.
(2)	United Nations Security Council	15 (5 Permanent and 10 NonPermanent)	(1) To maintain international peace and security. (2) To prepare policies for arms control. (3) To play a joint role along with the General Assembly in the appointments of the judges of the International Court of Justice and of the United Nations Secretary General.
(3)	International Court of Justice	15 judges	(1) To settle the disputes between two or more member nations of the United Nations. (2) To interpret international law authentically. (3) To advise the various organs or subsidiary bodies of the United Nations about legal issues.
(4)	Economic and Social Council	54 members	(1) Initiate discussions at the global level on issues like poverty, unemployment, economic and social inequality and suggest policies to tackle these problems. (2) Discuss issues like women’s questions, empowerment of women, human rights, fundamental freedoms, global trade, health related issues, etc., and make decisions. (3) Make efforts to establish cultural and educational cooperation at the international level. (4) Coordinate the functioning of the different organisations working in association with the United Nations.

Question 2.
Show the chronology of the establishment of the United Nations.

Answer:

Question 3.
Complete the following tree diagram about the United Nations.

Answer:

Class 9 Political Science Chapter 4 The United Nations Intext Questions and Answers

Answer the following in brief:

Question 1.
Did India participate in the conferences during the Second World War?
Answer:
India was among the original members of the United Nations that signed the Declaration by United Nations at Washington, D.C. on 1st January, 1942 and also participated in the United Nations Conference on International Organization at San Francisco from 25th April to 26th June 1945.

Question 2.
Which day is celebrated as United Nations day?
Answer:
United Nations was established on 24th October 1945. The day is now celebrated each year . around the world as United Nations Day.

Question 3.
Can the United Nations intervene militarily if there is a serious threat to international peace?
Answer:
The United Nations can’t intervene militarily if there is a serious threat to international peace. The UN, after approval by the Security Council, sends peacekeepers to regions where armed conflict has recently ceased or stalled to enforce the terms of peace agreements and to discourage combatants from resuming hostilities.

Question 4.
What steps have the United Nations taken to foster human rights and freedom?
Answer:
One of the UN’s primary purposes is to promote and encourage respect for human rights and to ensure fundamental freedoms for all without distinction on the basis of race, sex, language, or religion. In 1948, the General Assembly adopted a Universal Declaration of Human Rights. In 1979, the General Assembly adopted the Convention on the Elimination of All Forms of Discrimination against Women, followed by the Convention on the Rights of the Child, in 1989. United Nations Commission on Human Rights was formed in 1993 to oversee human rights issues for the UN.

Question 5.
Only one Indian has so far been the President of the UN General Assembly. Who is that person? When and at which session?
Answer:
Mrs. Vijayalakshmi Pandit is the only Indian so far who has been the President of the UN General Assembly, at the eighth session in 1953.

Activity:

Question 1.
Write the names of United Nations Secretary Generals until now.
Answer:
(i) Mr. Trygve Lie
(ii) Mr. Dag Hammarskjold
(iii) Mr. U. Thant
(iv) Mr. Kurt Waldheim
(v) Mr. Javier Perez de Cuellar
(vi) Mr. Boutros Boutros Ghali
(vii) Mr. Kofi Annan
(viii) Mr. Ban Ki Moon
(ix) Mr. Antonio Guterres

Question 2.
Is it necessary that the Secretary-General should be a citizen of the great powers/the big five?
Answer:
It is not necessary that the Secretary General should be a citizen of one of the great powers/ the big five. Here is the list of Secretary Generals with their countries: Mr. Trygve Lie (Norway) Mr. Dag Hammarskjold (Sweden)

• Mr. U. Thant (Mayanmar)
• Mr. Kurt Waldheim (Austria)
• Mr. Javier Perez de Cuellar (Peru)
• Mr. Boutros Boutros Ghali (Egypt)
• Mr. Kofi Annan (Ghana)
• Mr. Ban Ki Moon (South Korea)
• Mr. Antonio Guterres (Portugal)

Question 3.
Are citizens of a particular country given priority for being Secretary-General?
Answer:
The citizens of no particular country are given priority for being Secretary General.

Question 4.
Who is the current Secretary General and which country does he belong to?
Answer:
The current Secretary General is Antonio Guterres and he belongs to Portugal.

Class 9 Political Science Chapter 4 The United Nations Additional Important Questions and Answers

Choose the correct option from the given options and rewrite the statements:

Question 1.
The United Nations Organisation was founded on _______.
(a) August 9,1944
(b) October 24,1944
(c) October 24,1945
(d) December 10,1945
Answer:
(c) October 24,1945

Question 2.
The United Nations has ____ main organs.
(a) four
(b) five
(c) six
(d) seven
Answer:
(c) six

Question 3.
The United Nations has ______ official languages.
(a) four
(b) five
(c)six
(d) three
Answer:
(c)six

Question 4.
This language is not an official language of the United Nations
(a) French
(b) Spanish
(c) Arabic
(d) Italian
Answer:
(d) Italian

Question 5.
There are ______ permanent members in the Security Council.
(a) four
(b) five
(c)six
(d) seven
Answer:
(b) five

Question 6.
There are ________ non-permanent members in the Security Council.
(a) ten
(b) five
(c) fifteen
(d) seven
Answer:
(a) ten

Question 7.
The term of a non-permanent member of the Security Council is of ______.
(a) four years
(b) five years
(c) two years
(d) one year
Answer:
(c) two years

Question 8.
Which organ of the United Nations has suspended its operations since 1994?
(a) Trusteeship Council
(b) Economic and Social Council
(c) Secretariat
(d) International Court of Justice
Answer:
(a) Trusteeship Council

Question 9.
How many Judges are there in the International Court of Justice?
(a) 9
(b) 10
(c) 12
(d) 15
Answer:
(d) 15

Question 10.
What is the term of the United Nations Secretary General?
(a) 3 years
(b) 4 years
(c) 6 years
(d) 5 years
Answer:
(d) 5 years

Question 11.
UN Secretary General heads which principal organ of the United Nations Organisation?.
(a) General Assembly
(b) Security Council
(c) Economic and Social Council
(d) The Secretariat
Answer:
(d) The Secretariat

Question 12.
What is the term of a judge of the International Court of Justice?
(a) 9 years
(b) 4 years
(c) 6 years
(d) 5 years
Answer:
(a) 9 years

Question 13.
How many members does the Economic and Social Council have?
(a) 33
(b) 40
(c) 15
(d) 54
Answer:
(d) 54

Give the full forms of the following acronyms:

Question 1.
ILO:
Answer:
International Labour Organisation

Question 2.
FAO:
Answer:
Food and Agriculture Organisation

Question 3.
WHO:
Answer:
World Health Organisation

Question 4.
WB:
Answer:
World Bank

Question 5.
IMF:
Answer:
International Monetary Fund

Question 6.
UNICEF:
Answer:
United Nations Children’s Fund

Question 7.
UNESCO:
Answer:
United Nations Educational, Scientific and Cultural Organisation

State whether the following statements are true or false with reasons:

Question 1.
UNICEF is the main organ of UN.
Answer:
False.
(i) The United Nations has six main organs:

1. General Assembly
2. Security Council
3. Economic and Social Council
4. International Court of Justice
5. Trusteeship Council and
6. Secretariat.

(ii) UNICEF is an affiliated organisation of the United Nations. It works towards making nutritious food and health care available to children.

Explain the following concepts:

Question 1.
Millennium Development Goals
Answer:
The United Nations member nations came together in 2000 and decided upon the development goals for the new millennium. Some of the important goals are as follows:

• To eliminate poverty and hunger.
• To make the facilities of primary education available.
• To bring about women’s empowerment, reduce infant mortality rate.
• To take special care of the health of pregnant women.
• To fight diseases like AIDS, malaria, etc.
• To protect the environment and increase the cooperation between developed and developing countries.

Question 2.
International Criminal Court
Answer:
(i) The International Criminal Court is an inter-governmental organisation and an international tribunal.
(ii) Its headquarters are at The Hague in the Netherlands.
(iii) The International Criminal Court has the jurisdiction to prosecute individuals for international crimes of genocide, crimes against humanity and war crimes that are of concern to the international community.

Question 3.
International Court of Justice.
Answer:
(i) International Court of Justice means the judicial branch of the United Nations. The International Court of Justice is located at The Hague in the Netherlands.
(ii) There are 15 judges in the International Court of Justice.
(iii) They are chosen by the General Assembly and the Security Council. Every judge has tenure of nine years.
(iv) Functions:

• To settle the disputes between two or more member nations of the United Nations.
• To interpret international law authentically.
• To advise the various organs or subsidiary bodies of the United Nations about legal issues.

Question 4.
The UN Security Council.
Answer:
Security Council is one of the 6 main organs of the UN:

(i) There are 15 members in the Security Council. Of them, five are permanent members, while ten are non-permanent members.

(ii) The non-permanent members are chosen every two years by the General Assembly. America, Russia, England, France and China are permanent members of the Security Council. They have the veto power.

(iii) For any decision to be taken, the assent of all five permanent members and four non permanent members is necessary. If even one of the five permanent member uses his veto i.e. gives a negative vote, the decision cannot be taken.

(iv) Functions of the Security Council:

(a) The main responsibility of the Security Council is to maintain international peace and security.
The Security Council may suggest one among the following alternatives in situations of international conflict:

• End/resolve conflict and make efforts to establish peace
• Impose economic sanctions or take a decision of military action against the aggressor nation.

(b) To prepare policies for arms control.
(c) To play a joint role along with the General Assembly in the appointments of the judges of the International Court of Justice and of the United Nations Secretary General.

Complete the following table:

Question 1.

(1)	WHO	(a)	………….
(2)	UNESCO	(b)	…………..
(3)	UNICEF	(c)	…………
(4)	ILO	(d)	…………….

Answer:

(1)	WHO	(a)	World Health Organization
(2)	UNESCO	(b)	United Nations Educational Scientific and Cultural Organization
(3)	UNICEF	(c)	United Nations Children’s, Fund
(4)	ILO	(d)	International Labour Organization

Question 2.

(1)	New York	(a)	……….
(2)	Hague, Netherlands	(b)	…………
(3)	San Francisco	(c)	………..

Answer:

(1)	New York	(a)	Headquarters of UN
(2)	Hague, Netherlands	(b)	International Court of Justice
(3)	San Francisco	(c)	Drafting of UN Charter

Complete the flow chart:

Question 1.

Answer:

Complete the chart:

Question 1.

Answer:

Question 2.

Answer:

Answer the following in brief:

Question 1.
State the role of UN General Assembly as platform to discuss global problems.
Answer:
The United Nations General Assembly is a platform to discuss global problems because:

• Every year the General Assembly meets in its session from September to December.
• During the session, the General Assembly discusses important issues like environment, disarmament, etc
• The decisions in the General Assembly are taken by the majority. These decisions are in the form of resolutions.
• The significance of the General Assembly lies in being a platform for representatives of member nations to come together and discuss and make policy decisions on issues of global importance.

Question 2.
United Nations plays an important role in preservation of peace. Explain the statement.
Answer:
(i) The objective of the United Nations is to settle international conflict peacefully.

(ii) The United Nations Charter lays down the ways and means to be employed to achieve this goal.

(iii) It includes appointing an intermediary acceptable to the nations involved in the conflict, use the legal procedure, appoint an arbitrator to solve the dispute and if needed, to take recourse to military means and ensure that conflict will not occur again.

(iv) In modem times, human security has been threatened by terrorism, racist and religious conflict. As a result, the function of securing peace of the United Nations has acquired a lot of importance.

(v) The United Nations makes efforts to ensure that violence does not erupt in strife-tom areas and normalcy is restored as soon as possible, by (for example), starting schools, creating awareness among the people about human rights, making social, economic, political facilities available, conducting elections, etc.

Question 3.
How had India helped to solve international conflicts peacefully?
Answer:
(i) India had participated in the different Conferences that were held before the establishment of the United Nations.

(ii) India has participated in bringing issues like decolonisation, disarmament and racial segregation on the United Nations platform.

(iii) In 1946, India was the first country to raise . the question of racism in the United Nations.India has always led the discussions about the problems of undeveloped and developing countries.

(iv) India has always sent her troops to participate in the United Nations peacekeeping forces. Not just that, India has sent an all-woman peacekeeping force as well.

(v) It is evident from the foregoing analysis that India makes serious efforts to solve international conflicts by peaceful means.

Question 4.
What is the role of UNESCO?
Answer:
UNESCO, is an affiliated organisation of the United Nations works towards peace and security in the world by promoting cooperation between member countries in the fields of education, science and culture.

Question 5.
What are the principles of the United Nations?
Answer:
The United Nations is an organisation created by the coming together of sovereign nations. Naturally, it is based on certain principles or rules. They are as follows:

• All member nations will have the same status. There is no discrimination among nations based on geographical size, economic or military power.
• All member nations of the United Nations should respect the freedom and geographical unity of other member nations.
• All member nations should solve their international disputes and mutual issues peacefully.

Question 6.
What are the functions of the General Assembly?
Answer:
The United Nations General Assembly is a platform to discuss global problems. Functions of General Assembly are:

• To elect the non-permanent members of the Security Council.
• To choose the United Nations Secretary General and the judges of the International Court of Justice (ICJ) in consultation with the Security Council.
• To pass the annual budget of the United Nations.

Question 7.
What are the specialised agencies of UN?
Answer:
(i) Apart from these six major organs, there are many affiliated organisations of the United Nations that help it in its functions. They are called specialised agencies.

(ii) Working in specific areas, they help different nations in those areas.

(iii) The following are some of these important agencies:

• International Labour Organisation (ILO)
• Food and Agriculture Organisation (FAO)
• World Health Organisation (WHO)
• World Bank (WB)
• International Monetary Fund (IMF)
• United Nations Children’s Fund (UNICEF)
• United Nations Educational, Scientific and Cultural Organisation (UNESCO)

Question 8.
Why was the Trusteeship Council setup and why has it suspended its operations?
Answer:
(i) After the Second World War, the territories that were undeveloped were placed under the responsibility of the developed nations.

(ii) The latter were supposed to help bring about the development of the trust territories and once they attain independence from their colonies, help establish democracy.

(iii) The work of the Trusteeship Council is over as there are no trust territories left.

(iv) The work of the Trusteeship Council ended when Palau got independence on 1st November 1994.

Question 9.
Write about the phases in establishment of the United Nations.
Answer:
The United Nations is an international organisation of sovereign nations. It was established in the following manner:

(i) The Atlantic Treaty was signed between Prime Minister of England, Sir Winston Churchill and American, President Franklin D Roosevelt during the Second World War on 14th August 1941.

(ii) According to this treaty, a decision was taken to set up a permanent mechanism to establish international security after the Second World War was over.

(iii) Detailed discussions followed on this decision in two conferences among allied powers in 1944 and 1945.

(iv) A draft of the treaty to establish an international organisation was prepared.

(v) At San Francisco in America, representatives of fifty countries drafted the Charter of the United Nations after discussions.

(vi) As soon as the war was over, the Charter was signed on 24th October, 1945 and the United Nations was established.

Question 10.
Explain the characteristics of the Economic and Social Council.
Answer:
Economic and Social Council:

(i) The main objective of this organisation is to coordinate the economic and social policies of the United Nations.
(ii) The Council has 54 members. They are selected by the General Assembly.
(iii) Each member has a tenure of three years and each year, one-third of the members are newly chosen. Decisions are taken by majority vote.
(iv) Functions:

•  Initiate discussions at the global level on issues like poverty, unemployment, economic and social inequality and suggest policies to tackle these problems.
• Discuss issues like women’s questions, empowerment of women, human rights, fundamental freedoms, global trade, health related issues, etc. and make decisions.
• Make efforts to establish cultural and educational cooperation at the international level.
• Coordinate the functioning of the different organisations working in association with the United Nations.

Activity:

Question 1.
Name the UN Secretary-General who later on became the President of his country.
Answer:
Mr. Kurt Waldheim of Austria.

Question 2.
Name the UN Secretary-General who died in an air-crash.
Answer:
Dag Hammarskjold of Sweden, died on September 18, 1961, during a Congo Mission.

Balbharti Maharashtra State Board Class 9 Science Solutions Chapter 6 Classification of Plants Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 9 Science Solutions Chapter 6 Classification of Plants

Class 9 Science Chapter 6 Classification of Plants Textbook Questions and Answers

1. Match the proper terms from columns A and C with the description in column B.

2. Complete the sentences by filling in the blanks and explain those statements.
(angiosperms, gymnosperms, spore, Bryophyta, thallophyta, zygote)
a. ……………….. plants have soft and fiber-like body.

b. ……………….. is called the ‘amphibian’ of the plant kingdom.
Answer:
Bryophyta plant is called the ‘amphibian’ of the plant kingdom

c. In pteridophytes, asexual reproduction occurs by ……………….. formation and sexual reproduction occurs by ………………..formation.
Answer:
Spore, zygote: Pteridophyta plants show alteration of generation. One generation reproduces by spore-formation and the next generation reproduces sexually by zygote formation.

d. Male and female flowers of ……………….. are borne on different sporophylls of the same plant.
Answer:
Gymnosperms bear their male and female flowers on different sporophylls of the same plant

3. Answer the following questions in your own words.

a. Write the characteristics of subkingdom Phanerogams.
Answer:

• Plants which have special structures for reproduction and produce seeds are called Phanerogams.
• In these plants, after the process of reproduction, seeds are formed which contain the embryo and stored food.
• During the germination of the seed, the stored food is used for the initial growth of the embryo.
• Depending upon whether seeds are enclosed in a fruit or not phanerogams are classified into gymnosperms and angiosperms.

b. Distinguish between monocots and dicots.
Answer:

	Dicots	Monocots
Seed	Two cotyledons	Single cotyledon
Root	Well developed, primary root (Taproot)	Fibrous roots
Stem	Strong, hard. e.g. Banyan tree	Hollow, e.g. Bamboo False, e.g. Banana Disc-like, e.g. Onion.
Leaf	Reticulate venation	Parallel venation
Flower	Flowers with 4 or 5 parts or in their multiples (tetramerous or pentamerous)	Flowers with 3 parts or in multiples of three (trimerous).

c. Write a paragraph in your own words about the ornamental plants called ferns.
Answer:

• Ferns belong to the group of plants called Pteridophyta.
• They have well-developed roots, stem and leaves but do not bear flowers and fruits.
• They have separate tissues for the conduction of food and water.
• They reproduce with the help of spores formed along the back or posterior surface of their leaves.
• They reproduce asexually by spore formation and sexually by zygote formation.

d. Sketch, label and describe the Spirogyra.

e. Write the characteristics of the plants belonging to division Bryophyta.
Answer:

• Bryophyta group of plants are called the amphibians of the plant kingdom because they grow in moist soil but need water for reproduction.
• These plants are thalloid, multicellular and autotrophic.
• They reproduce by spore-formation.
• Their plant body structure is flat, ribbon-like, long, without true roots, stem and leaves.
• Instead, they have stem-like or leaf-like parts and root-like rhizoids.
• They do not have specific tissues for the conduction of food and water.
• Examples: Moss (Funaria), Anthoceros, Riccia etc.?

4. Sketch and label the figures of the following plants and explain them into brief.
Marchantia, Funaria, Fern, Spirogyra.

Question 1.
Spirogyra.
Answer:

• Spirogyra belongs to the division thallophyta. They are called as algae.
• It grows mainly in water.
• It does not have specific parts like root-stem- leaves-flowers but are autotrophic due to the presence of chlorophyll.
• The plant body of Spirogyra is soft and fibre-like.
• It has spirally arranged chloroplasts in its cell.

Question 2.
Funaria and Marchantia (Bryophyta)
Answer:

• These plants are called ‘amphibians’ of the plant kingdom because they grow mostly in soil and need water for reproduction.
• They do not have specific tissues for the conduction of food and water.
• The plant body is fiat, ribbon-like long, without true roots, stem and leaves
• Instead, they have stem-like or leaf-like parts and root like rhizoids.

Question 3.
Fern (Pteridophyta):
Answer:

• They have well-developed roots, stem and leaves for the conduction of food and water.
• They do not bear flowers and fruits.
• They reproduce with the help of spores present along the back or posterior surface of the leaves.

5. Collect a monocot and dicot plant available in your area. Observe the plants carefully and describe them in scientific language.

6. Which criteria are used for the classification of plants? Explain with reasons.
Answer:
Criteria for classification of plants:

• If plants do not bear flowers, fruits and seeds, they are non-seed bearing plants. If they bear flowers, fruit and seeds, they are seed-bearing plants.
• Presence or absence of conducting tissues- Plants such as pteridophytes, gymnosperms and angiosperms which possess conducting tissues are included in vascular plants whereas thallophytes and bryophytes which do not possess conducting tissues are included under non-vascular plants.
• Depending upon whether the seeds are enclosed in fruit or not, plants are classified as gymnosperms (naked-seeds) and angiosperms (seeds covered by fruit)
• Depending upon the number of cotyledons in seeds, plants are classified into dicotyledons and monocotyledons

Class 9 Science Chapter 6 Classification of Plants Intext Questions and Answers

Can you recall?

Question 1.
How have living organisms been classified?
Answer:
(i) Organisms have been classified based on the following:

• Cell structure
• Body Organisation
• Mode of nutrition
• Reproduction

(ii) Organisms are also classified at kingdom level and groups and subgroups.

Activity-based questions

Question 1.
You may have seen a lush green soft carpet on old walls, bricks and rocks in the rainy season. Scrape it gently with a small ruler, observe it under a magnifying lens and discuss.
Answer:

• It shows considerable tissue complexity and is differentiated into two main parts: a root and a shoot.
• They have a variety of specialized tissues within these two regions of the body.
• Same kind of cells are seen throughout the whole body except reproductive cells.

Question 2.
You may have seen ferns among the ornamental plants in a garden. Take a leaf of a fully grown fern and observe it carefully.
Answer:

• New leaves typically expand by the unrolling in a tight spiral manner.
• The anatomy of fern leaves can either be simple or highly divided.
• They show the presence of spores formed along the back or posterior surface of their leaves.

Question 3.
Observe all garden plants like Cycas, Christmas tree, Hibiscus, Lily, etc. and compare them. Note the similarities and differences among them. Which differences did you notice in gymnosperms and angiosperms?
Answer:
Cycas and Christmas tree are gymnosperms, whereas Hibiscus and lily are angiosperms.

1. Similarities: These plants have special structures for reproduction and produce seeds. During the germination of the seed, the stored food is used for the initial growth of the embryo.
2. Differences: In gymnosperms, reproductive organs have cones whereas in angiosperms reproductive organs have flowers.
3. In gymnosperms, seeds are without natural coverings whereas in angiosperms seeds are enclosed in natural coverings called fruits.

Question 4.
Soak the seeds of corns, beans, groundnut, tamarind, mango, wheat, etc. in water for 8 to 10 hrs. After they are soaked, check each seed to see whether it divides into two equal halves or not and categorize them accordingly.
Answer:
Monocots: com, wheat (it cannot be divided into equal halves)
Dicots: beans, groundnut, tamarind and mango (it can be divided into two equal halves)

Class 9 Science Chapter 6 Classification of Plants Additional Important Questions and Answers

Choose and write the correct option:

Question 1.
The five-kingdom classification was proposed b7
(a) Robert Whittaker
(b) Robert Hooke
(c) Eichler
(d) Louis Pasteur
Answer:
(a) Robert Whittaker

Question 2.
In 1883, classified plants into two sub-kingdoms.
(a) Robert Whittaker
(b) Alexander Fleming
(c) Eichler
(d) Robert Hooke
Answer:
(c) Eichler

Question 3.
Ulothrix, ulva, sargassum belong to
(a) Bryophyta
(b) Thallophyta
(c) Pteridophyta
(d) Gymnosperms
Answer:
(b) Thallophyta

Question 4.
is a bryophyte.
(a) Ulva
(b) Nephrolepis
(c) Funaria
(d) Equisetum
Answer:
(c) Funaria

Question 5.
In the seeds are naked.
(a) Pteridophyta
(b) Angiosperms
(c) Gymnosperms
(d) Bryophyta
Answer:
(c) Gymnosperms

Question 6.
In the flowers are reproductive organs.
(a) Angiosperms
(b) Gymnosperms
(c) Pteridophyta
(d) Bryophyta
Answer:
(a) Angiosperms

Question 7.
In the flowers are tetramerous or pentamerous.
(a) Monocotyledons
(b) Dicotyledons
(c) Gymnosperms
(d) Pteridophyta
Answer:
(b) Dicotyledons

Question 8.
In monocotyledonous plants, the stem is
(a) hollow
(b) false
(c) disc-like
(d) all of these.
Answer:
(d) all of these

Question 9.
Lycopodium belongs to
(a) Thallophyta
(b) Bryophyta
(c) Gymnosperms
(d) Pteridophyta
Answer:
(d) Pteridophyta

Question 10.
Leaves of show reticulate venation.
(a) Bamboo
(b) Banana
(c) Onion
(d) Banyan
Answer:
(d) Banyan

Question 11.
Various types of fungi like yeasts and moulds are included in the group
(a) Thallophyta
(b) Halophyte
(c) Xenophyta
(d) Angiosperms
Answer:
(a) Thallophyta

Question 12.
Bryophytes have a root-like structure called
(a) Nodes
(b) Rhizoids
(c) Nodules
(d) Aerenchyma
Answer:
(b) Rhizoids

Question 13.
reproduce with the help of spores formed along the back or posterior surface of their leaves.
(a) Halophyta
(b) Pteridophyta
(c) Thallophyta
(d) Angiosperms
Answer:
(b) Pteridophyta

Question 14.
In ……………………….., the reproductive organs cannot be seen.
(a) Pteridophyta
(b) Cryptogams
(c) Thallophyta
(d) Angiosperms
Answer:
(b) Cryptogams

Question 15.
are mostly evergreen, perennial and woody.
(a) Pteridophyta
(b) Thallophyta
(c) Gymnosperms
(d) Angiosperms
Answer:
(c) Gymnosperms

Question 16.
Gymnosperms bear male and female flowers on different of the same plant.
(a) Branches
(b) Roots
(c) Sporophylls
(d) Flowers
Answer:
(c) Sporophylls

Question 17.
In the seeds are not enclosed by fruit.
(a) Pteridophyta
(b) Thallophyta
(c) Gymnosperms
(d) Angiosperms
Answer:
(c) Gymnosperms

Question 18.
In the seeds are enclosed by fruit.
(a) Pteridophyta
(b) Thallophyta
(c) Gymnosperms
(d) Angiosperms
Answer:
(d) Angiosperms

Question 19.
The plants whose seeds cannot be divided into equal parts are called
(a) Algae
(b) Fungus
(c) Dicotyledons
(d) Monocotyledons
Answer:
(d) Monocotyledons

Question 20
The plants whose seeds can be divided into equal parts are called
(a) Algae
(b) Fungus
(c) Dicotyledons
(d) Monocotyledons
Answer:
(c) Dicotyledons

Find the odd one out:

Question 1.
Ulothrix, Ulva, Nephrolepis, Sargassum
Answer:
Nephrolepis: It belongs to division Pteridophyta whereas the others belong to division thallophyta.

Question 2.
Funaria, Marchantia, Anthoceros, Spirogyra
Answer:
Spirogyra:

Question 3.
Marsilea, Pteris, Lycopodium, Riccia
Answer:
Riccia:

Question 4.
Cycas, Mango, Apple, Banyan
Answer:
Cycas:

Question 5.
Onion, Papaya, Wheat, Green peas
Answer:
Green peas:

Complete the analogy:

(1) Spirogyra : Thallophyta : : Riccia :
(2) Moss : Bryophyta : : Selaginella :
(3) Nephrolepis : Pteridophyta :: Ulothrix :
(4) Pteridophyta : Roots :: Bryophyta :
(5) Gymnosperms : naked seeds : : Angiosperms :
(6) Dicotyledon : Reticulate venation : : Monocotyledon:
(7) Bamboo stem: Hollow:: Onion Stem:
(8) Monocotylendon : Tap root:: Dicotyledon :
Answer:
(1) Bryophyta
(2) Pteridophyta
(3) Thallophyta
(4) Rhizoids
(5) Covered seeds
(6) Parallel venation
(7) Disc like
(8) Fibrous roots

Difference between:

Question 1.
Thallophyta and Bryophyta
Answer:

Thallophyta	Bryophyta
These plants grow mainly in water	They grow in moist soil but need water for reproduction

Question 2.
Gymnosperms and Angiosperms
Answer:

Gymnosperms	Angiosperms
No natural covering on seeds	Seeds are formed in fruits

Question 3.
Algae and Moss
Answer:

Algae	Moss
These plants mainly grow in water.	These plants need water for reproduction.

State whether the following statements are true or false. Correct the false statements:

(1) Thallophyta are called as the amphibians of the plant kingdom.
(2) Fungi like yeasts and moulds are included in division bryophyta.
(3) Moss (Funaria) belongs to division bryophyta.
(4) Bryophyta have specific tissues for conduction of food and water.
(5) Plants belonging to Thallophyta group are only unicellular.
(6) Pteridophytes have well developed roots, stems and leaves.
(7) Pteridophytes reproduce with the help of spores formed along the back or posterior surface of their leaves.
(8) Nephrolepis belongs to division Pteridophyta.
(9) Depending upon whether seeds are enclosed in a fruit or not, phanerogams are classified into monocots and dicots.
(10) Gymnosperms are mostly evergreen, perennial and woody.
(11) Gymnosperms bear male and female flowers on different sporophylls of different plants.
(12) In Angiosperms, the seeds are covered by fruits.
(13) Dicotyledonous plants show reticulate venation.
(14) Moncotyledonous plants have trimerous flowers.
(15) In dicotyledonous plants, the stem is strong and hard.
Answer:
(1) False. Thallophyta plants grow mainly in water.
(2) False. Fungi like yeasts and moulds are included in division thallophyta.
(3) True
(4) False. Bryophyta do not have specialised tissuesfor conduction of food and water.
(5) False. Plants belonging to thallophyta group may be unicellular or multicellular.
(6) True
(7) True
(8) True
(9) False. Depending whether seeds are enclosed in. a fruit or not, angiosperms are classified into monocots and dicots.
(10) True
(11) False. Gymnosperms bear male and female flowers on different sporophylls of the same plant.
(12) True
(13) False. Dicotyledonous plants show parallel venation.
(14) True
(15) True.

Give name

Question 1.
What are ornamental plants are called?
Answer:
Ferns

Question 2.
Plants with two cotyledons are called.
Answer:
Dicots

Question 3.
Plants with single cotyledon are called.
Answer:
Monocots

Question 4.
Type of venation showed by hibiscus plant leaves
Answer:
Reticulate venation

Question 5.
Type of venation showed by lily plant leaves
Answer:
Parallel venation

One line answers

Question 1.
Which plants are mostly evergreen, perennial and woody?
Answer:
Gymnosperms are mostly evergreen, perennial and woody.

Question 2.
Which type of venation showed by dicot plants?
Answer:
Leaves of dicot plants show reticulated venation.

Question 3.
Which type of venation showed by monocot plants?
Answer:
Leaves of monocot plants show parallel venation

Question 4.
How are angiosperms classified into monocot and dicot?
Answer:
Depending whether seeds and enclosed in fruit or not, angiosperms are classified into monocot and dicot

Question 5.
In which division are fungi like moulds and yeast classified?
Answer:
Fungi like moulds and yeast classified in division thallophyta.

Question 6.
Plants belonging to which group may be unicellular or multicellular?
Answer:
Plants belonging to thallophyta group may be unicellular or multicellular

Give scientific reason

Question 1.
Thallophyta plants have thin and fibre like body
Answer:
Thallophyta: These plants grow mainly in water i.e. fresh water as well as in saline water, therefore they usually have a soft and fibre-like (filamentous) body.

Question 2.
Bryophyta plants are called the amphibian plants.
Answer:
Bryophyta: They grow in moist soil but need water for reproduction. Therefore, they are called ‘amphibians of plant kingdom’.

Question 3.
Gymnosperms bear their male and female flowers on different sporophylls of the same plant
Answer:
Gymnosperms: As these plants do not take the assistance of pollinators i.e. vectors, the male and female flowers are present on the different sporophyll of the same plant for successful fertilisation.

Write note on

Question 1.
August W. Eichler
Answer:
In 1883, Eichler, a botanist, classified the Kingdom Plantae into two subkingdoms. As a result, two subkingdoms, cryptogams and phanerogams were considered for plant classification.

Question 2.
Thallophyta
Answer:
These plants grow mainly in water. This group of plants, which do not have specific parts like root-stem-leaves-flowers but are autotrophic due to the presence of chlorophyll, is called algae. Algae show great diversity. They may be unicellular or multicellular, and microscopic or large. Examples of algae are Spirogyra, Ulothrix, Ulva, Sargassum, etc. Some of these are found in fresh water while some are found in saline water. These plants usually have a soft and fibre-like body. Various types of fungi like yeasts and moulds which do not have chlorophyll are also included in this group.

Question 3.
Bryophyta
Answer:
This group of plants is called the amphibians’ of the plant kingdom because they grow in moist soil but need water for reproduction. These plants are thalloid, multicellular and autotrophic. They reproduce by spore formation. The structure of the plant body of bryophytes is flat, ribbon-like long, without true roots, stem and leaves. Instead, they have stem-like or leaf-like parts and root-like rhizoids. They do not have specific tissues for conduction of food and water. Examples are Moss (Funaria), Marchantia, Anthoceros, Riccia, etc.

Question 4.
Pteridophyta
Answer:
Plants from this group have well developed roots, stem and leaves and separate tissues for conduction of food and water. But, they do not bear flowers and fruits. They reproduce with the help of spores formed along the back or posterior surface of their leaves. Examples are ferns like Nephrolepis, Marsilea, Pteris, Adiantum, Equisetum, Selaginella, Lycopodium, etc. These plants reproduce asexually by spore-formation and sexually by zygote formation. They have a well-developed conducting system.

Question 5.
Phanerogams
Answer:
Plants which have special structures for reproduction and produce seeds are called phanerogams. In these plants, after the process of reproduction, seeds are formed which contain the embryo and stored food. During germination of the seed, the stored food is used for the initial growth of the embryo. Depending upon whether seeds are enclosed in a fruit or not, phanerogams are classified into gymnosperms and angiosperms.

Question 6.
Gymnosperms
Answer:
Gymnosperms are mostly evergreen, perennial and woody. Their stems are without branches. The leaves form a crown. These plants bear male and female flowers on different sporophylls of the same plant. Seeds of these plants do not have natural coverings, i.e. these plants do not form fruits and are therefore called gymnosperms. (gymnos: naked, sperms: seeds). Examples Cycas, Picea (Christmas tree), Thuja (Morpankhi), Pinus (Deodar), etc.

Question 7.
Angiosperms
Answer:
The flowers these plants bear are their reproductive organs. Flowers develop into fruits and seeds are formed within fruits. Thus, these seeds are covered; hence, they are called angiosperms (angios: cover, sperms: seeds). The plants whose seeds can be divided into two equal halves or dicotyledons are called dicotyledonous plants and those whose seeds cannot be divided into equal parts are called monocotyledonous plants.

Complete the flow chart.

Question 1.
Living Organisms

Answer:

Question 2.
Kingdom: Plantae

Answer:

Distinguish between:

Question 1.
Bryophyta and Pteridophyta:
Answer:

Bryophyta	Pteridophyta
Bryophytes grow in soil but need water for reproduction.	Pteridophytes grow in soil.
Plant body is without specific parts like true roots, stem and leaves.	Plant body is differentiated into true roots, stem and leaves.
Conducting tissues for food and water absent.	Conducting tissues for food and water present.
Examples: Moss (Funaria), Marchantia, Anthoceros, etc.	Examples: Nephrolepis, Marsilea, Pteris, Adiantum, Lycopodium etc.

Question 2.
Angiosperms and Gymnosperms.
Answer:

Angiosperms	Gymnosperms
(i) In Angiosperms, the stems have branches.	(i) In Gymnosperms, the stems are without branches.
(ii) Reproductive organs are flowers.	(ii) Reprodcutive organs are cones.
(iii) Seeds are enclosed in natural coverings, i.e., fruits.	(iii) Seeds are not enclosed in natural coverings.
(iv) Examples: Mango, Bamboo, etc.	(iv) Examples: Cycas, Picea etc.

Question 3.
Cryptogams and Phanerogams.
Answer:

Cryptogams	Phanerogams
(iii) Their reproductive organs are hidden.	(iii) Their reproductive organs are exposed.
(iii) They reproduce by forming spores.	(iii) They reproduce by forming seeds.
(iii) They are less evolved plants.	(iii) They are highly evolved plants.
(iv) They are divided into Thallophyta,	(iv) They are divided into Gymnosperms and
Bryophyta, Pteridophyta.	Angiosperms.

Distinguish between:

Question 1.
Thallophyta
Answer:
Spirogvra, Ulothrix, Ulva, Sargassum

Question 2.
Bryophyta
Answer:
Moss (Funaria), Marchantia, Anthoceros, Riccia

Question 3.
Pteridophyta
Answer:
Nephrolepis, Marsilea, Pteris, Adiantum, Equisetum, Selaginella, Lycopodium

Question 4.
Gymnosperms
Answer:
Cycas, Picca (Christmas tree), Thuja (Morpankhi), Pinus (Deodar)

Question 5.
Angiosperms
Answer:
Tamarind, Mango, Apple, Lemon

Question 6.
Monocot plants
Answer:
Bamboo, bananas, corn, daffodils, garlic, ginger, grass, lilies, onions, orchids, rice, sugarcane, tulips, and wheat

Question 7.
Dicot plants
Answer:
Rose, sunflower, grapes, strawberries, tomatoes, peas, peanuts and potatoes

Observe the figure and answer the questions

1. Dicot Plants

Question 1.
What are the characteristics of the above plants in terms of root system?
Answer:
Well developed, primary root (Tap root)

Question 2.
What are the characteristics of the above plants in terms of flowers?
Answer:
Flowers with 4 or 5 parts or in their multiples (tetramerous or pentamerous)

Question 3.
What are the characteristics of the above plants in terms of leaf venations?
Answer:
Reticulate Venation

Question 4.
What are the characteristics of the above plants in terms of type of stem?
Answer:
Strong and hard

Question 5.
What are the characteristics of the above plants in terms of seed?
Answer:
Two cotyledons

Question 6.
Give example of the following types of plants
Answer:
Rose, sunflower, grapes, strawberries, tomatoes, peas, peanuts and potatoes

2. Monocot Plants

Question 1.
What are the characteristics of the above plants in terms of root system?
Answer:
Fibrous roots

Question 2.
What are the characteristics of the above plants in terms of flowers?
Answer:
Flowers with 3 parts or in multiples of three (trimerous).

Question 3.
What are the characteristics of the above plants in terms of leaf venations?
Answer:
Parallel Venation

Question 4.
What are the characteristics of the above plants in terms of type of stem?
Answer:
Hollow, False or Disc-like

Question 5.
What are the characteristics of the above plants in terms of seed?
Answer:
Single cotyledons

Question 6.
Give example of the following types of plants
Answer:
Bamboo, bananas, com, daffodils, garlic, ginger, grass, lilies, onions, orchids, rice, sugarcane, tulips, and wheat

3. Spirogyra

Question 1.
Which division of plants does this plant come under?
Answer:
This plant come under Division I Thallophyta.

Question 2.
Where does this plant grow?
Answer:
These plants grow mainly in water.

Question 3.
Are these types of plants unicellular or multicellular?
Answer:
They may be unicellular or multicellular and microscopic or large.

Question 4.
Are these types of plant autotropic?
Answer:
They are autotrophic due to the presence of chlorophyll but types of fungi like yeasts and moulds which do not have chlorophyll are also included in this group.

Question 5.
Do these plants have a root-stem-leaves-flowers system?
Answer:
They do not have specific parts like root-stem- leaves-flowers.

Question 6.
How is the body of these types of plants?
Answer:
These plants usually have a soft and fibre-like body.

4. Funaria

Question 1.
Which division of plants does this plant come under?
Answer:
This plant come under Division II Bryophyta.

Question 2.
Where does this plant grow?
Answer:
They grow in moist soil but need water for reproduction.

Question 3.
What are these group of plants called in the plant kingdom?
Answer:
This group of plants is called the ‘amphibians’ of the plant kingdom.

Question 4.
Are these types of plant autotropic?
Answer:
They reproduce by spore formation.

Question 5.
Do these plants have root-stem-leaves-flowers system?
Answer:
The structure of the plant body of bryophytes is flat, ribbon-like long, without true roots, stem and leaves.

Question 6.
What do these plants have instead of roots?
Answer:
They have root like rhizoids.

5. Fern

Question 1.
Which division of plants does this plant come? under?
Answer:
This plant come under Division III Pteridophy ta.

Question 2.
Where does this plant grow?
Answer:
They grow in soil.

Question 3.
How do these plants reproduce?
Answer:
These plants reproduce asexually by spore- formation and sexually by zygote formation.

Question 4.
Do these plants produce flowers and fruits?
Answer:
They do not bear flowers and fruits.

Question 5.
Do these plants have root-stem-leaves-flowers system?
Answer:
Plants from this group have well developed roots, stem and leaves and separate tissues for conduction of food and water.

Question 6.
Where are the spores formed in the plants body?
Answer:
The spores formed along the back or posterior surface of their leaves.

6. Cycas

Question 1.
Which division of plants does this plant come under?
Answer:
This plant come under Division III Phanerogams Division I Gymnosperms.

Question 2.
Explain structure of these types of plants?
Answer:
Gymnosperms are mostly evergreen perennial and woody.

Question 3.
How is stem and leaves of these types of plants?
Answer:
Their stems are without branches and the leaves form a crown.

Question 4.
Where are the male and female flowers located?
Answer:
These plants bear male and female flowers on different sporophylls of the same plant.?

Question 6.
Give some examples of these types of plants?
Answer:
Rose, sunflower, grapes, strawberries, tomatoes, peas, peanuts and potatoes

7. Monocot and Dicot plants

Question 1.
Which division of plants does this plant come under?
Answer:
ThisplantcomeunderDivisionlllPhanerogams Division II Angiosperms

Question 2.
How are the seeds of these types of planis?
Answer:
The seeds are formed within fruits thus these seeds are covered

Question 3.
How can we classify the plants according to their seeds in this division?
Answer:
The plants whose seeds can be divided into two equal halves or dicotyledons are called dicotyledonous plants and those whose seeds cannot be divided into equal parts are called monocotyledonous plants.

Question 4.
How the venations are present on the leaves of these types of plants?
Answer:
These plants bear parallel or reticulated venations on the leaves.

Question 5.
How is the root system of these types of plants?
Answer:
The root systems of these types of plant are tap roots or fibrouš roots.

Complete the paragraph

Question 1.
Thallophyta plants grow mainly in …………….. . This group of plants, which do not have specific parts like root-stem-leaves-flowers but are autotrophic due to the presence of …………….., is called algae. Algae show great diversity. They may be unicellular or …………….., and microscopic or large. Examples of algae are Spirogyra, Ulothrix, Ulva, Sargassum, etc. Some of these are found in fresh water while some are found in saline water. These plants usually have a …………….. and fibre-like body. Various types of …………….. like yeasts and moulds which do not have …………….. are also included in this group.
Answer:
Thallophyta plants grow mainly in water. This group of plants, which do not have specific parts like root-stem-leaves-flowers but are autotrophic due to the presence of chlorophyll, is called algae. Algae show great diversity. They may be unicellular or multicellular, and microscopic or large. Examples of algae are Spirogyra, Ulothrix, Ulva, Sargassum, etc. Some of these are found in fresh water while some are found in saline water. These plants usually have a soft and fibre-like body. Various types of fungi like yeasts and moulds which do not have chlorophyll are also included in this group.

Question 2.
…………….. group of plants is called the amphibians’ of the plant kingdom because they grow in moist soil but need …………….. for reproduction. These plants are thalloid, multicellular and autotrophic. They reproduce by …………….. formation. The structure of the plant body of bryophytes is flat, ribbon?like long, without true …………….., stem and leaves. Instead, they have stem-like or leaf?like parts and root-like ……………. . They do not have specific …………….. for conduction of food and water. Examples are Moss (Funaria), Marchantia, Anthoceros, Riccia, etc.
Answer:
Bryophyta group of plants is called the ‘amphibians’ of the plant kingdom because they grow in moist soil but need water for reproduction. These plants are thalloid, multicellular and autotrophic. They reproduce by spore formation. The structure of the plant body of bryophytes is flat, ribbon-like long, without true roots, stem and leaves. Instead, they have stem-like or leaf-like parts and root-like rhizoids. They do not have specific tissues for conduction of food and water. Examples are Moss (Funaria), Marchantia, Anthoceros, Riccia, etc.

Question 3.
Plants from Pteridophyta group have well developed roots, stem and leaves and separate …………….. for conduction of food and water. But,
they do not bear …………….. and ……………… They reproduce with the help of …………….. formed along the back or posterior surface of their leaves. Examples are ferns like Nephrolepis, Marsilea, Pteris, Adiantum, Equisetum, Selaginella, Lycopodium, etc. These plants reproduce …………….. by spore-formation and sexually by …………….. formation. They have a well-developed conducting system.
Answer:
Plants from Pteridophyta group have well developed roots, stem and leaves and separate tissues for conduction of food and water. But, they do not bear flowers and fruits. They reproduce with the help of spores formed along the back or posterior surface of their leaves. Examples are ferns like Nephrolepis, Marsilea, Pteris, Adiantum, Equisetum, Selaginella, Lycopodium, etc. These plants reproduce asexually by spore-formation and sexually by zygote formation. They have a well-developed conducting system.

Question 4.
Phanerogams plants which have special structures for …………….. and produce …………….. In these plants, after the process of reproduction, seeds are formed which contain the …………….. and stored food. During germination of the seed, the stored food is used for the initial growth of the embryo. Depending upon whether seeds are enclosed in …………….. a or not, phanerogams are classified into …………….. and ……………. .
Answer:
Phanerogams plants which have special structures for reproduction and produce seeds. In these plants, after the process of reproduction, seeds are formed which contain the embryo and stored food. During germination of the seed, the stored food is used for the initial growth of the embryo. Depending upon whether seeds are enclosed in a fruit or not, phanerogams are classified into gymnosperms and angiosperms.

Question 5.
Gymnosperms are mostly …………….., perennial and woody. Their stems are without …………….. The leaves form a …………….. These plants bear male and female flowers on different …………….. of the same plant …………….. of these plants do not have natural coverings, i.e. these plants do not form …………….. and are therefore called gymnosperms. (gymnos: naked, sperms: seeds). Examples Cycas, Picea (Christmas tree), Thuja (Morpankhi), Pinus (Deodar), etc.
Answer:
Gymnosperms are mostly evergreen, perennial • and woody. Their stems are without branches. The leaves form a crown. These plants bear male and female flowers on different sporophylls of the same plant. Seeds of these plants do not have natural coverings, i.e. these plants do not form fruits and are therefore called gymnosperms. (gymnos: naked, sperms: seeds). Examples Cycas, Picea (Christmas tree), Thuja (Morpankhi), Pinus (Deodar), etc.

Question 6.
The flowers of Angiosperms plants bear are their …………….. organs Flowers develop into …………….. and seeds are formed within …………….. . Thus, these seeds are ……………..; hence, they are called angiosperms (angios: cover, sperms: seeds). The plants whose seeds can be divided into two equal halves or dicotyledons are called …………….. plants and those whose seeds cannot be divided into equal parts are called …………….. plants.
Answer:
The flowers of Angiosperms plants bear are their reproductive orgAnswer: Flowers develop into fruits and seeds are formed within fruits. Thus, these seeds are covered; hence, they are called angiosperms (angios: cover, sperms: seeds). The plants whose seeds can be divided into two equal halves or dicotyledons are called dicotyledonous plants and those whose seeds cannot be divided into equal parts are called monocotyledonous plants.

Answer the questions in detail:

Question 1.
Write the characteristics of Thallophyta.
Answer:

• Thallophyta plants grow mainly in water.
• The group of plants, which do not have specific parts like root-stem-leaves-flowers but are autotrophic due to the presence of chlorophyll are called algae.
• Algae show great diversity They may be unicellular or multicellular and microscopic or large.
• Some of these are found in freshwater while some are found in saline water.
• Various types of fungi like yeasts and moulds which do not have chlorophyll are also included in this group.
• Examples: Spirogyra, Ulothrix, Ulva, etc.

Question 2.
Write the characteristics of Gymnosperms.
Answer:

• Gymnosperms are mostly evergreen, perennial and woody.
• Their stems are without branches.
• The leaves form a crown.
• These plants bear male and female flowers on different sporophylls of the same plant.
• Seeds of these plants do not have natural coverings, i.e. these plants do not form fruits and are therefore called gymnosperms (gmnos: naked, sperms: seeds)
• Examples: Cycas, Picea (christmas tree), Thuja, Pinus (deodar), etc.

Make concept diagram

Question 1.
Plant classification
Answer:

Question 2.
Taxonomy of carnivorous 1ant
Answer:

Question 3.
Taxonomy of mango plant
Answer:

Balbharti Maharashtra State Board Class 9 History Solutions Chapter 5 Education Notes, Textbook Exercise Important Questions and Answers.

Maharashtra State Board Class 9 History Solutions Chapter 5 Education

Class 9 History Chapter 5 Education Textbook Questions and Answers

1. Choose the right option and rewrite the sentence:

Question 1.
The Scientist who developed the Param – 8000 supercomputer _________.
(a) Dr Vijay Bhatkar
(b) Dr R. H. Dave
(c) P. Parthasarathy
(d) None of the above
Answer:
(a) Dr. Vijay Bhatkar

Question 2.
The magazine Jeevan Shikshan is published by _______.
(a) Balbharati
(b) University Education Commission
(c) MSCERT
(d) NCERT
Answer:
(c) MSCERT

Question 3.
The educational institution called IIT is famous for educational in the area of _______.
(a) Agriculture
(b) Medicine
(c) Skilled managers
(d) Engineering
Answer:
(d) Engineering

2. Do as directed.

Question 1.
Complete the table below with details about individuals in the education field and their work.

Individual	Work
First education minister of India	Maulana Abul Kalam Azad.
—————–	Chairman of the University Education Commission
Prof Sayyad Rauf	…………..
……………………..	Kosbad Project

Answer:

Individual	Work
First education minister of India	Maulana Abul Kalam Azad.
Dr. Sarvapalli Radhakrishna	Chairman of the University Education Commission
Prof Sayyad Rauf	Preparation of common state-wide curriculum for Std. I to VII for Maharashtra.
Anutai Wagh	Kosbad Project

Question 2.
Obtain information about the National Council of Educational Research and Training, from the internet, and present it in the form of a timeline.
Answer:

1st September 1961	The National Council of Educational Research and Training (NCERT) was established in Delhi.
27th January 1967	The Maharashtra State Bureau of Textbook Production and Curriculum Research (Balbharati) was established in Pune.
1986	The National Policy on Education was adopted.
1988	The ‘Primary Education Curriculum was prepared.
1995	The Competency-based primary education curriculum.
1975	India met with success in its attempt to use a satellite for the purpose of education.
1970	The United Nations declared the year 1970 as the International Education Year. A seminar was organised in New Delhi and led to the establishment of an open university.
1974	The government appointed a committee under the chairmanship of P. Parthasarathy

3. Explain the following statements giving reasons for your answer:

Question 1.
The District Primary Education Programme was undertaken.
Answer:
(i) In 1994, the District Primary Education Programme (DPEP) was started with the objective of universalisation of primary education. It was implemented in seven States including Maharashtra.

(ii) The plan envisaged 100% attendance in primary schools, arresting student drop-out, education for girls and for the physically handicapped.

(iii) It included programmes such as research on and evaluation of primary education, alternative education, creating societal awareness, etc.

Question 2.
The NCERT was established.
Answer:
(i) National Council of Educational Research and Training (NCERT) was established in Delhi on the 1st of September 1961.

(ii) Its main objective is to help the Central Government in matters of school education in the context of a comprehensive policy and in implementing educational schemes. The NCERT was given the responsibility of educational research and development, training, extension, educational programmes, restructuring of school curriculum and textbooks.

(iii) It has played a central role in designing school curricula and textbooks with the cooperation of the Central Board of Secondary Education (CBSE).

(iv) It provides guidance and cooperation in the area of primary and secondary education to the state governments.

(v) It has been involved in designing workbooks and handbooks for teachers, in teacher training, in developing teaching-learning techniques and conducting talent search examinations at the national level.

Question 3.
The farmers were benefited by the Indian Agricultural Research Institute.
Answer:
(i) The Indian Agricultural Research Institute was given the status of a University in 1958 and work began in departments such as the development of the agriculture sector, research, well-equipped laboratories, soil science, agricultural sciences, economic botany and other departments.

(ii) Research also began on wheat, pulses, oilseeds, vegetables and many other problems.

(iii) Its most significant achievement is the fundamental research it has conducted on the methods of taking multiple crops in a year, which has been of great benefit to farmers.

4. Write notes:

Question 1.
Indira Gandhi National Open University
Answer:
(i) Indira Gandhi National Open University (IGNOU) was established with the objective that the stream of education should make
its way into every average household of the country.

(ii) The United Nations had declared 1970 as the International Education Year. In the same year, a seminar was organised in New Delhi on the subject of Open University by the Government of India Departments of Education and Social Welfare, Information and Broadcasting, University Grants Commission along with UNESCO. The idea of establishing an open university evolved in this seminar.

(iii) In 1974, the government appointed a committee under the chairmanship of P. Parthasarathy and the Open University took shape on 20 September, 1985 in accordance with its recommendations and suggestions. It was named after Prime Minister Indira Gandhi. Those who are unable to get a college education in the formal way are given concessions in eligibility criteria, age and other conditions for admission to this university.

(iv) In 1990, the IGNOU started an audio-visual distance education programme through Akashvani and Doordarshan. It conducted more than one thousand curricula of various branches.
It provides facilities for education through 58 training centres in the country and 41 centres in foreign countries.

Question 2.
Kothari Commission
Answer:
(i)In 1964 a Commission was appointed under the Chairmanship of Dr D. S. Kothari. Dr J. P. Naik made valuable contributions to the work of this Commission.

(ii)The Commission also recommended the 10+2+3 pattern for secondary, higher secondary and university education. This system was implemented from 1972.

(iii)The Commission also suggested a uniform national system of education, the inclusion of the mother tongue, Hindi and English in education, as well as continuing education, adult education, education by correspondence and open universities to make education trickle down to the lowest rungs of society.

(iv)It also recommended increased provision in the government’s budget for expenditure on education of neglected sections like the scheduled castes and tribes. Maharashtra government adopted the 10+2+3 pattern in 1972 and conducted the first Std X Board exam in 1975.

Question 3.
Bhabha Atomic Research Centre
Answer:
(i) Bhabha Atomic Research Centre (BARC) has conducted valuable research in the fields of nuclear physics, solid state physics, spectroscopy, chemical and life sciences.

(ii) It also started a school to train scientists for setting up nuclear reactors.

Question 4.
Balbharati
Answer:
(i) The Maharashtra State Bureau of Textbook Production and Curriculum Research (Balbharati) was established in Pune on 27 January 1967.

(ii) Balbharati prepares textbooks for school children. Textbooks are made in eight languages, namely, Marathi, Hindi, English, Urdu, Kannad, Sindhi, Gujarati and Telugu. ‘Kishor’, a monthly magazine for children, is also published by Balbharati.

5. Answer the following questions in detail:

Question 1.
Which programmes were included in the Operation Blackboard scheme?
Answer:
(i) The government made funds available to help improve the standard of the schools and to fulfil minimum educational needs such as at least two proper classrooms, toilets, one of the two teachers to be female, a blackboard, maps, laboratory apparatus, a small library, a playground, sports equipment, etc. This scheme helped the primary education system to gain some momentum.

(ii) In 1994, this scheme was expanded and provision was made for one additional classroom and for appointing one more teacher in schools with an enrolment of more than 100 students, with priority given to girls’ schools, schools with a majority of scheduled caste and tribe students and schools in rural areas.

(iii) It was also made binding upon the State government to appoint female teachers to fifty per cent of the posts in schools.

Question 2.
What role do agriculture schools/colleges play in the development of agriculture?
Answer:
(i) The Indian Agricultural Research Institute was given the status of a University in 1958 and work began in departments such as the development of the agriculture sector, research, well-equipped laboratories, soil science, agricultural sciences, economic botany and other departments. Research also began on wheat, pulses, oilseeds, vegetables and many other problems.

(ii) Its most significant achievement is the fundamental research it has conducted on the methods of taking multiple crops in a year, which has been of great benefit to farmers.

Question 3.
Describe with examples of the progress that India has made in the field of medicine.
Answer:
(i) The Indian Council for Medical Research (ICMR) was established for conducting research in the medical field. It was given the responsibility of cooperating with universities, medical colleges, government and non-government research institutes and giving them guidance and financial support for research activities.

(ii) Twenty-six centres were started in different parts of the country for research on various diseases. Their research has made it possible to control tuberculosis and leprosy.

(iii) The All India Institute of Medical Sciences (AIIMS) was established to give further impetus to advanced education and research in medicine.

(iv) It was given the responsibility of undergraduate and postgraduate courses in medicine. Colleges for undergraduate and postgraduate education in most branches of medicine, good research facilities and well- equipped hospitals are the significant features of this institute.

(v) The institute also provides medical treatment to the common people at nominal rates. It has established special colleges for training in nursing, and super-speciality centres for treatment of disorders of the heart, brain and eyes.

(vi) For further development of the medical field, the Medical Council of India was restructured in 1958 and was entrusted with the task of determining criteria for quality of medical education, its supervision and inspection.

(vii) These institutes have the responsibility of conducting research on various diseases, developing tests and standardisation of medicines.

Question 4.
Write a note on the curricular and co-curricular activities conducted in your school.
Answer:
(i) Languages – Our school motivates us to participate in theatres or plays organised on works of Shakespeare and Munshi Premchand. We also take part in elocution and poetry recitation competitions to enhance public speaking. Our school makes every child read the newspaper headlines from Marathi and English dailies in the auditorium turn wise.

(ii) Maths and Science – Scientific experiments mentioned in our textbook are practically performed by each of us under the supervision of our teachers. On Sundays, our Math teachers take special classes on Vedic Maths. Our school has also organised trips to Nehru Planetarium and ‘Jantar Mantar’ to give us an understanding of the astronomical aspects of science. Every year our school conducts Homi Bhabha scholarship exam. A display of the best 25 science projects is done in the school hall.

(iii) Social Studies – Field studies are taken up to explain to us the topography of Indian landscapes. The school library holds a large number of book and documentaries over world history trips to museums and historical places.

Class 9 History Chapter 5 Education Additional Important Questions and Answers

Choose the correct option from the given options and rewrite the statements:

Question 1.
In 1995, the _____ scheme was started to provide proper nourishment for the students.
(a) free ration
(b) foodgrain subsidy
(c) mid-day meal
(d) medical-check up
Answer:
(c) mid-day meal

Question 2.
_______was the first education minister of Independent India.
(a) Vallabhbhai Patel
(b) Maulana Abdul Kalam Azad
(c) Sachchidanand Sinha
(d) J.B.Kriplani
Answer:
(b) Maulana Abdul Kalam Azad

Question 3.
_____ recommended increased provision in government’s budget for expenditure on education of neglected sections like the SC/ST.
(a) University Education Commission
(b) Mudaliar Commission
(c) National Council of Educational Research and Training
(d) Kothari Commission
Answer:
(d) Kothari Commission

Question 4.
_______, a scientist with ISRO played an important role in providing satellite education.
(a) K. Kasturirangan
(b) Eknath Chitnis
(c) A. S. Kirankumar
(d) G. Madhavan Nair
Answer:
(b) Eknath Chitnis

Question 5.
In 1990 _____ started an audio-visual distance education programme through Akashwani and Doordarshan.
(a) ISRO
(b) NCERT
(c) IGNOU
(d) CSIR
Answer:
(c) IGNOU

Question 6.
The National Institute for Research in Mathematical and Physical Sciences’ in ______ was established in 1962.
(a) Chandigarh
(b) Kerala
(c) Karnataka
(d) Tamil Nadu
Answer:
(d) Tamil Nadu

Question 7.
India’s first IIT was setup at _______ at West Bengal in 1951.
(a) Kharagpur
(b) Midnapore
(c) Hooghly
(d) Howrah
Answer:
(a) Kharagpur

Identify and write the wrong pair in the following sets:

Question 1.
(1) TCS – obtained an American contract for software production.
(2) FTII – Systematic training in all aspects of film-making.
(3) C-DAC – developed Param – 8000
(4) IIM – imparting training in industrial design.
Answer:
Wrong Pair : IIM – imparting training in industrial design.

Question 2.
(1) The Advanced Centre for Treatment Research and Education in Cancer – Branch of Tata Memorial Centre
(2) AIIMS – advanced education and research in medicine.
(3) DPEP – Charts showing learning competencies upto Std.V
(4) National Policy on Education 1986 – Common core curriculum was framed for all states.
Answer:
Wrong Pair : DPEP – Charts showing learning competencies upto Std.

Question 3.
(1) National Institute of Design – Ahmedabad
(2) Maharashtra State Board of Secondary and Higher Secondary Education – Pune
(3) The National Institute for Research in the Mathematical and Physical Science – Delhi
(4) Indian Institute of Technology – West Bengal
Answer:
Wrong Pair: The National Institute for Research in the Mathematical and Physical Science – Delhi

Question 4.
(1) J.P. Naik – Kothari Commission
(2) P. Parthasarthy – Committee on Open University
(3) Sayyad Rauf – Drafted common state wide curriculum
(4) Dr. Sarvapalli Radhakrishnan – Director of NCERT.
Answer:
Wrong Pair : Dr. Sarvapalli Radhakrishnan Director of NCERT.

Question 5.
(1) Dave Committee – minimum levels of learning.
(2) The Art Department – designing workbooks and hand books.
(3) Kosbad project – Education of Adivasis
(4) Council of Scientific and Industrial Research – Promote scientific research.
Answer:
Wrong Pair : The Art Department – designing workbooks and hand books.

Question 6.
(1) MSCERT – Jeevan Shikshan
(2) Balbharati – Kishor
(3) The Maharashtra State Board of Secondary and Higher Secondary Education – Countrywide classroom.
(4) SITE – Satellite Education.
Answer:
Wrong Pair : The Maharashtra State Board of Secondary and Higher Secondary Education – Countrywide classroom

Question 7.
(1) Tarabai Modak – Kuranshalas
(2) Anutai Wagh – Kosbad Projects
(3) Eknath Chitnis – Education Minister
(4) R. H. Dave – Competency based Primary Education Curriculum.
Answer:
Wrong Pair: Eknath Chitnis – Education Minister

Complete the concept maps:

Question 1.
Objectives of Education:
Answer:

Question 2.
Central Council for Research in Indian Medicine and Homeopathy:
Answer:

Question 3.
Departments of the Indian Agricultural Research Institute:
Answer:

Question 4.
Role of Dave Committee:
Answer:

Question 5.
Features of the IIT
Answer:

Question 6.
IIMs in India
Answer:

Question 7.
Concept map of basic responsibilities of NCERT
Answer:

Write short notes:

Question 1.
AIIMS
Answer:
(i) The All India Institute of Medical Sciences (AIIMS) was established to give further impetus to advanced education and research in medicine.

(ii) It was given the responsibility of undergraduate and post-graduate courses in medicine.

(iii) Colleges for undergraduate and postgraduate education in most branches of medicine, good research facilities and well-equipped hospitals are the significant features of this institute.

(iv) The institute also provides medical treatment to the common people at nominal rates.

(v) It has established special colleges for training in nursing, and super-speciality centres for treatment of disorders of the heart, brain and eyes.

(vi) For further development of the medical field, the Medical Council of India was restructured in 1958 and was entrusted with the task of determining criteria for quality of medical education, its supervision and inspection.

Question 2.
Achievements of CSIR
Answer:
(i) In the post-independence period in 1950, the Council of Scientific and Industrial Research (CSIR) was established with the objective to promote scientific research in the country and to take the benefits of the research to all the people.

(ii) The achievements of the CSIR include making the ink used for marking voters’ fingers during elections, medicines for malaria, elephantiasis and tuberculosis, water purification technology, reduction in the time required for bamboo production.

(iii) It also used DNA fingerprinting for the first time in India, conducted a genetic study of the Adivasis of the Andamans and proved that those tribes are 60,000 years old and developed the earthquake early warning system.

(iv) It has also played an important role in the use of neem as a pesticide, use of turmeric for healing wounds and in the case of the patents for varieties of rice.

(v) The CSIR has prepared a digital encyclopedia of Indian traditional knowledge and made it available in eight international languages.

Question 3.
NCERT
Answer:
(i) National Council of Educational Research and Training (NCERT) was established in Delhi on the 1st of September 1961.

(ii) Its main objective is to help the Central Government in matters of school education in the context of a comprehensive policy and in implementing educational schemes. The NCERT was given the responsibility of educational research and development, training, extension, educational programmes, restructuring of school curriculum and textbooks.

(iii) It has played a central role in designing school curricula and textbooks with the cooperation of the Central Board of Secondary Education (CBSE). ’

(iv) It provides guidance and cooperation in the area of primary and secondary education to the state governments.

(v) It has been involved in designing workbooks and handbooks for teachers, in teacher training, in developing teaching-learning techniques and conducting talent search examinations at the national level.

Read the passage and answer the questions and answer the questions based on it.

Passage I

National Council of Educational Research and Training. This body was established in Delhi on the 1st of September 1961. Its main objective is to help the Central Government in matters of school education in the context of a comprehensive policy and in implementing educational schemes. The NCERT was given the responsibility of educational research and development, training, extension, educational programmes, restructuring of school curriculum and textbooks. It has played a central role in designing school curricula and textbooks with the cooperation of the Central Board of Secondary Education (CBSE). It provides guidance and cooperation in the area of primary and secondary education to the state governments. It has been involved in designing workbooks and handbooks for teachers, in teacher training, in developing teaching-learning techniques and conducting talent search examinations at the national level.
SCERTs were established in all States on the lines of the NCERT. The Maharashtra State Council of Educational ‘Research and Training was established in Pune, This institute performs various functions such as , improving the standard of primary education, in service training of teachers, training in the areas of syllabii and evaluation, vocational guidance for students after Std X and Std XII exams and other , educational functions This institute is known as the , academic authority. It brings out a periodical called Jeevan Sikshan. ‘

Question 1.
What was the main objective behind establishment of NCERT?
Answer:
The main objective behind establishment of NCERT is to help the central government in matters of school education in the context of a comprehensive policy and in implementing educational schemes.

Question 2.
SCERT was established only in Maharashtra State on the lines of the NCERT. Identify True or False.
Answer:
False.

Question 3.
State 4 research institutes in India.
Answer:
Following are the 4 research institutes in India:

• Council of Scientific & Industrial Research.
• Bhabha Atomic Research Centre.
• Indian Council of Medical Research.
• Indian Agricultural Research Institute.

Passage II

National Policy on Education 1986: According to this policy, certain changes of a fundamental nature were brought about in primary, secondary and higher , secondary education in keeping with the changing needs of society. Under this policy, a common core curriculum was framed for all States. The expectation , is that, by this means, all students in India will get equal educational opportunity. There is scope in the national curriculum for individual States to bring in flexibility in accordance with their cultural, geographical and historical needs.
The ‘Primary Education Curriculum 1988’ was prepared on the basis of the plan of action designed at the national level for the effective implementation of the National Policy on Education 1986. The competency based primary Education curriculum 1995: Even as the Primary Education Curriculum , 1988 was being implemented, a Committee was formed at the national level with Dr. R. H. Dave as its Chairman, to determine minimum levels of learning, The Dave as Committee developed charts of minimum , levels of learning in language, mathematics and environmental studies up to Std V. The charts showed the sequence of learning of the competencies meant for each class.
Use of a satellite: In 1975, India met with success in its attempt to use a satellite for the purpose of education, Eknath Chitnis, a scientist with ISRO, played an , important role in it.
SITE (Satellite Instructional Television Experiment) , was undertaken for educational purposes under the leadership of the Space Applications Centre at Ahmedabad. The concept of satellite education came , out of this experiment. America had helped India in , this programme. The programme helped to make provisionsforagoodstandardofeducationinruralareas.

Question 1.
What was done to implement the National Policy on Education 1986?
Answer:
For the effective implementation of National Policy on Education 1986, the Primary Education Curriculum 1988 was prepared on the basis of the action plan formulated at the National level.

Question 2.
How did the Dave committee determine the minimum levels of learning?
Answer:
To determine the minimum levels of learning the Dave committee developed charts in language, mathematics and environmental studies upto Std. V. Sequential learning competencies were depicted on these charts to set standards through levels of learning.

Question 3.
Who is your favourite educationist? State his/ her educational ideas which impacted the society.
Answer:
(i) My favourite educationist are Rabindranath Tagore, Dr. Annie Besant and Dr. Sarvapalli Radha Krishnan.

(ii) They all enlightened the society with their educational ideas and deeds. Dr. Annie Besant in particular was iconic.

(iii) Her ideas of education were imbibed with political freedom, women’s liberation and universal brotherhood. Her teachings of ‘Home Rule’ and ‘theosophy’ impacted our society during British Rule. She taught these ideas through political lectures to motivate the youth.

Answer the following questions in detail:

Question 1.
What does the District Primary Education Programme envisage?
Answer:
(i) In 1994, the District Primary Education Programme (DPEP) was started with the objective of universalisation of primary education. It was implemented in seven States including Maharashtra.

(ii) The plan envisaged 100% attendance in primary schools, arresting student drop-out, education for girls and for the physically handicapped.

(iii) It included programmes such as research on and evaluation of primary education, alternative education, creating societal awareness, etc.

Question 2.
State the contribution of Tarabai Modak in educating adivasis.
Answer:
(i) Tarabai Modak began work in the field of education in Bordi and Kosbad.
(ii) She started Anganwadis for Adivasi children.
(iii) She worked hard to bring in the Teaming by doing’ method, to start kuranshalas (meadow schools) and to spread vocational technical education.

Question 3.
What purpose did the Kosbad Project serve?
Answer:
(i) Anutai Wagh established an institution at Kosbad for the progress of Adivasis in Thane district.
(ii) It is known as the Kosbad Project.
(iii) She started creches, nurseries, primary schools, adult education classes, balsevika training schools, etc. for the education of Adivasis.

Question 4.
What was proposed by the Mudaliar Commission?
Answer:
(i) In 1952-53, the Mudaliar Commission was appointed.
(ii) At that time, the pattern of education consisted of 11 + 4 years for the first degree or of 11 + 1 + 3 years.
(iii) The Commission studied secondary education, the nature of the curriculum, medium of instruction, teaching methodology and made certain recommendations.
(iv) This Commission proposed the concept of Higher Secondary Education. However, it was found difficult to implement it all over the country.

Question 5.
State the recommendation of Kothari Commission.
Answer:
(i) The Kothari Commission recommended the 10+2+3 pattern for secondary, higher secondary and university education. This system was implemented from 1972.

(ii) The Commission also suggested a uniform national system of education, the inclusion of the mother tongue, Hindi and English in education, as well as continuing education, adult education, education by correspondence and open universities to make education trickle down to the lowest rungs of society.

(iii) It also recommended increased provision in the government’s budget for expenditure on education of neglected sections like the scheduled castes and tribes.

Question 6.
What do you know about the Education Board of your state?
Answer:
(i) The Maharashtra State Board of Secondary and Higher Secondary Education was established on the 1st of January 1966 at Pune.
(ii) This Board conducts the school leaving examinations of Std. X and Std. XII.
(iii) It also publishes a periodical called ‘Shikshan Sankraman’.

Question 7.
State the functions of MSCERT.
Answer:
(i) The Maharashtra State Council of Educational Research and Training was established in Pune.
(ii) This institute performs various functions such as improving the standard of primary education,
in-service training of teachers, training in the areas of syllabi and evaluation, vocational guidance for students after Std X and Std XII exams and other educational functions.

Question 8.
How did the concept of satellite education evolve in India?
Answer:
(i) SITE (Satellite Instructional Television Experiment) was undertaken for educational purposes under the leadership of the Space Applications Centre at Ahmedabad.
(ii) The concept of satellite education came out of this experiment. America had helped India in this programme.
(iii) The programme helped to make provisions for a good standard of education in rural areas.

Question 9.
Discuss the responsibilities of Indian Council for Medical Research.
Answer:
(i) Indian Council for Medical Research (ICMR) was established for conducting research in the medical field.
(ii) It was given the responsibility of cooperating with universities, medical colleges, government and non-government research institutes and giving them guidance and financial support for research activities.

Question 10.
Which institute works for advanced research in cancer?
Answer:
The Advanced Centre for Treatment, Research and Education in Cancer is a branch of the Tata Memorial Centre. It functions as the national centre for treatment, research and education in relation to cancer.

Observe the pictures/personality and write relevant information:

Question 1.

Answer:
(i) Kothari Commission recommended the 10+2+3 pattern for secondary, higher secondary and university education.
(ii) The objectives of Education were :

• Modernisation of Education.
• Social and national integration.
• Nurture of social, moral, spiritual values.
• Education and Productivity.
• Securing and strengthening of democracy.

(iii) The following are the other recommendations made by the Kothari commission:

• A uniform national system of education
• inclusion of mother tongue (along with Hindi and English)
• Continuing education
• Adult education
• Education by correspondence
• Open Universities.

Question 2.

Answer:
(1) The open university was established with the objective that the stream of education should make its way into every average household of the country.

(2) In 1974, the government appointed a committee under the chairmanship of P. Parthasarthy and open university took shape on 20th September 1985 in accordance with its recommendations and suggestions.
It was named after Prime Minister – Indira Gandhi.

(3) In 1990, IGNOU started an audio-visual distance education programme through Akashwani and Doordarshan.

(4) It provides facilities for education through 58 centres in the country and 41 centres in foreign countries.

Question 3.

Answer:
(1) CSIR was established with the objective to promote scientific research in the country and to take the benefits of the research to all the people.

(2) CSIR conducted research in fields like:

• Physics, chemistry, pharmaceuticals, food processing and mining

(3) The achievements of CSIR include:

• Making the ink used for marking voter’s fingers during elections
• Medicines for malaria, elephantiasis and tuberculosis
• water purifying technology
• DNA fingerprinting for the first time in India.

(4) CSIR has prepared a digital encylopoedia of Indian traditional knowledge and made it available in eight international languages.