Category: Maharashtra State Board Notes

By going through these Maharashtra State Board 12th Science Chemistry Notes Chapter 8 Transition and Inner Transition Elements students can recall all the concepts quickly.

Maharashtra State Board 12th Chemistry Notes Chapter 8 Transition and Inner Transition Elements

d – Series :

• 3d-Series : ₂₁Sc to ₃₀Zn
• 4d-Series: ₃₉Y to ₄₈Cd
• 5d-Series : ₅₇La to ₈₀Hg
• 5d-Series : ₈₉Ac to ₁₁₂Cn

Electronic Configuration :

• 3d-Series: [Ar] 3d^1-10 4s^1-2
• 4d-Series:[Kr] 4d^1-10 5s^1-2
• 5d-Series: [Xe] 4f¹⁴ 5d^1-10 6s^1-2
• 6d- Series: [Rn] 5f¹⁴ 6d^1-10 7s^1-2

Electronic configuration	Expected	Observed
(i) 24Cr (ii) 29Cu	[Ar] 3d44y2 [Ar] 3d9 As2	[Ar] 3d5 As1 [Ar] 3d10 As1

For 3d-Series :

• Atomic radii decrease from Sc to Cu
• Ionic radii decrease from Sc to Ni
• First ionisation enthalpy increases from Sc to Zn.

Transition elements show variable oxidation states common being + 2.

1 Bohr Magneton (B.M) = \(\frac{e h}{4 \pi m_{\mathrm{e}} c}\)

Spin only formula : \(\mu=\sqrt{n(n+2)}\)

KMnO₄

Preparation from MnO₂

Strong oxidising agent

• in acidic medium
• in neutral or weakly alkaline medium

K₂Cr₂O₇ :

Preparation from chromite ore :

Metallurgy :

1. Metal extraction processes –

• Pyrometallurgy
• Hydrometallurgy
• Electrometallurgy

2. Steps involved in the extraction of pure metal-

• Concentration
• Conversion of an ore into oxides
• Reduction of an ore
• Refining of metals

3. Extraction of iron from haematite ore by Blast furnace

f-Block elements :

Lanthanoids : _{5 8}Ce to _{7 1}Lu
Actinoids : _{9 0}Th to _{1 0 3}Lr

Electronic configuration :

Lanthanoids : [Xe] 4f^1-14 5d^0-1 6s²
Actinoids : [Rn] 5f^1-14 6d^0-1 7s²

Position in periodic table :

f-Block elements	Group	Period
Lanthanoids	3	6
Actinoids	3	7

Lanthanoid contraction, Actinoid contraction

By going through these Maharashtra State Board 12th Science Chemistry Notes Chapter 7 Elements of Groups 16, 17 and 18 students can recall all the concepts quickly.

Maharashtra State Board 12th Chemistry Notes Chapter 7 Elements of Groups 16, 17 and 18

Atomic, physical and chemical properties of group 16,17 and 18 elements-

Group 16 elements-

O to Po:

• Atomic size, M.P., B.P., Density increase
• Ionisation enthalpy, electronegativity decrease
• Hydrides (H₂X) : Bond angle, bond energy decrease Reducing power increases
• Oxides (EO₂, EO₃) (E = S, Se, Te, Po)
• Halides (EX₆, EX₄, EX2) (E = S, Se, Te)
• Reacts with metals to form compounds

Allotropes :

• O : O₂, O₃ (Ozone)
• S : Rhombic, monoclinic, cyclo-S6
• Se : red, grey
• Te : Crystalline, amorphous
• Po : α, β

Group 17 elements-

F to I (At):

• Atomic size, Density increase
• Ionisation enthalpy, electronegativity decrease
• (Haloacids, HX) : Acidity, reducing character increase Stability decrease
• Oxides of halogens (Most of them are unstable)
• Interhalogen compounds
• Metal halides

Group 18 elements-

He to Xe (Rn):

• Atomic size, density, M.P., B.P., increase
• Ionisation enthalpy, decreases
• Chemically inert towards hydrogen, oxygen
• krypton and Xenon form fluorides

Oxoacids of sulphur-

Oxoacids of halogens-

O₂ – Preparation –

O₂ –
2Ca + O₂ → 2CaO
C + O₂ → CO₂

Simple oxides-

Acidic (CO₂, SO₂, etc.)
Basic (CaO, BaO, etc.)
Amphoteric (Al₂O3, Zno, etc.)

Ozone –

Oxidising property: (i) PbS_(S) + 4O_3(g) → PbSO₄ + 4O_2(g)
(ii) 2KI + H₂O +O₃ →2KOH + I₂ + O₂
(iii) NO_(g) + O_3(g) → NO_2(g) + O_2(g)
Bleaching property O₃ → O + O₂
Reducing property : BaO₂ + O₃ → BaO + 2O₂
H₂O₂ + O₃ → H₂O + 2O₂

SO₂ – preparation

S_(S) + O_2(g) → SO_2(g)
Na₂SO₃ + H₂SO_4(aq) → Na₂SO₄ + H₂O_(I) + SO_2(g)

SO₂ –

2NaoH + SO₂ → Na₂SO₃ + H₂O
Na₂SO₃ + H₂O + SO₂ → 2NaSO₃
2Fe³⁺ + SO₂ + 2H₂O → 2Fe²⁺ + SO₄ ^2- + 4H⁺

H₂SO₄ (Manufacture)—Contact process—(Catalyst V₂O₅)

H₂SO₄ – 

C + 2H₂SO₄ → CO₂ + 2H₂O + 2SO₂
S + 2H₂SO₄ → 3SO₂ + 2H₂O
Cu + 2H₂SO₄ → CuSO₄ + SO₂ + 2H₂O

NaCl + H₂SO₄ → NaHSO₄ + HCl
KNO₃ + H₂SO₄ → KHSO₄ + HNO₃
CaF₂ + H₂SO₄ → CaSO₄ + 2HF

Chlorine Preparation –

MnO₂ + 4HCl → MnCl₂ + Cl₂ + 2H₂O
4NaCl + MnO₂ + 4H₂SO₄ → 4NaHSO₄ + MnCl₂ + 2H₂O + Cl₂

NaCl ⇌ Na⁺ + Cl^–

Cl₂ –

2Al + 3Cl₂ → 2AlCl₃
P₄ + 6Cl₂ → 4PCl₃
H₂ + Cl₂ → 2HCl
8NH₃ (Excess) + 3Cl₂ → 6NH₄Cl + N₂
2Ca(OH)₂ + 2Cl₂ → Ca(OCl)₂ + CaCl₂ + 2H₂O

2FeSO₄ + H₂SO₄ + Cl₂ → Fe₂(SO₄)₃ + 2HCl
Cl₂ + H₂O → HCl + HOCl

HCl : Preparation –

HCl –

HCl_(g) + H₂O_(l) → H₃O⁺ + Cl^–(aq)
NH₃ + HCl → NH₄Cl
Au + 4H⁺ + NO^–₃ + 4Cl^– → AuCl^–₄ + NO + 2H₂O

Interhalogen Compounds-

Compounds of Xenon-

Compound	Hybridisation	Structure
(i) XeF2	sp3d	linear
(ii) XeF4	sp3d2	square planar
(iii) XeF6	sp3d3	distorted octahedral
(iv) Xe03	sp3	pyramidal

 

By going through these Maharashtra State Board 12th Science Chemistry Notes Chapter 6 Chemical Kinetics students can recall all the concepts quickly.

Maharashtra State Board 12th Chemistry Notes Chapter 6 Chemical Kinetics

→ For a reaction, aA + bB → cC + dD
Average rate = \(-\frac{1}{a} \frac{\Delta[\mathrm{A}]}{\Delta t}=-\frac{1}{b} \frac{\Delta[\mathrm{B}]}{\Delta t}=-\frac{1}{c} \frac{\Delta[C]}{\Delta t}=-\frac{1}{d} \frac{\Delta[\mathrm{D}]}{\Delta t}\)

→ Rate law : Rate = k [A]^a x [B]^b

→ k = \(\frac{2.303}{t}\) log₁₀ \(\frac{[\mathrm{A}]_{0}}{[\mathrm{~A}]_{\mathrm{t}}}\) (For first order reaction)

→ t_1/2 = \(\frac{0.693}{k}\) (For first order reaction)

→ k = \(\frac{[\mathrm{A}]_{0}-[\mathrm{A}]_{t}}{t}\) (For zero order reaction)

→ t_1/2 = \(\frac{[\mathrm{A}]_{0}}{2 k}\)(For zero order reaction)

→ k = Ae^-Ea/RT (Arrhenius equation)

→ log₁₀k =log₁₀A – \(\frac{E_{a}}{2.303 R \mathrm{~T}}\)

→ log₁₀\(\frac{k_{2}}{k_{1}}=\frac{E_{a}\left(T_{2}-T_{1}\right)}{2.303 R \times T_{1} \times T_{2}}\)

By going through these Maharashtra State Board 12th Science Chemistry Notes Chapter 5 Electrochemistry students can recall all the concepts quickly.

Maharashtra State Board 12th Chemistry Notes Chapter 5 Electrochemistry

→ Electrical conductance (G) = \(\frac{1}{R}\)Ω^-1 2 or S

→ Cell constant = \(\frac{l}{a}\) cm^-1 (m^-1)

→ Conductivity(k) = \(\frac{\text { Cell constant }}{\text { Resistance }}\)

→ Molar Conductivity(∧_m) = \(\frac{\kappa}{C}\) (k in Ω^-1 m^-1 and C in mol^-3) OR
∧_m = \(\frac{\kappa \times 1000}{C}\) (k in Ω^-1 cm^-1 and C in mol dm^-3)

→ Kohlrausch’s law : ∧₀ = \(\lambda_{+}^{0}+\lambda_{-}^{0}\)

→ Degree of dissociation (α) = \(\frac{\Lambda_{\mathrm{m}}}{\Lambda_{0}}\)

→ Dissociation constant (Ka) = \(\frac{\bigwedge_{\mathrm{m}}^{2} C}{\Lambda_{0}\left(\Lambda_{0}-\Lambda_{\mathrm{m}}\right)}\)

→ 1 Faraday = 96500 C (Change on one mole of electrons)

→ E°_cell = E°_red (cathode) – E°_red (anode)

→ E_Mⁿ⁺/M = E°_Mⁿ⁺/M – \(\frac{0.0592}{n}\) log₁₀[Mⁿ⁺]

→ E_cell = E°_cell – \(\frac{0.0592}{n} \log _{10} \frac{[\text { Products }]}{[\text { Reactants }]}\)

→ ΔG° = – nFE°_cell

→ ΔG = -nFE_cell

→ ΔG°= -RTlnK

→ E°_cell = \(\frac{0.0592}{n}\) log₁₀K
For spontaneous cell reaction : E_cell > 0; ΔG < 0

By going through these Maharashtra State Board 12th Science Chemistry Notes Chapter 4 Chemical Thermodynamics students can recall all the concepts quickly.

Maharashtra State Board 12th Chemistry Notes Chapter 4 Chemical Thermodynamics

→ W = -P (V₂ – V₁) = -PΔV (For expansion)

→ W = P (V₂ – V₁) = PΔV (For compression)

→ W_max = -2.303 nRT log₁₀ \(\frac{V_{2}}{V_{1}}\)

→ W_max= -2.303 nRT log₁₀ \(\frac{P_{1}}{P_{2}}\)

→ ΔU = q + W

→ H = U + PV

→ ΔH = ΔU + PΔV

→ ΔH = ΔU + ΔnRT

→ Hess’s law : ΔH = ΔH₁ + ΔH₂ + ΔH₃

→ ΔS = \(\frac{q_{\mathrm{rev}}}{T}=\frac{\Delta H}{T}\)

→ G = H – TS

→ ΔG = ΔH – TΔS

→ ΔG°= – 2.303 RTlog₁₀K

→ (i) ΔG = 0, the system is at equilibrium
(ii) ΔG < 0, the process is spontaneous
(iii) ΔG > 0, the process is non-spontaneous.

By going through these Maharashtra State Board 12th Science Chemistry Notes Chapter 3 Ionic Equilibria students can recall all the concepts quickly.

Maharashtra State Board 12th Chemistry Notes Chapter 3 Ionic Equilibria

→ Formulae on Ostwald’s dilution law:

→ K_w = [H₃O⁺] × [OH^–], at 25°C K_w = 1 × 10^-14

→ pH = -log₁₀[H⁺]; pOH = -log₁₀[OH^–]

→ pH + pOH = 14

→ Acidic buffer solution: pH = PK_a + log₁₀ \(\frac { [salt] }{ [acid] }\)

→ Basic buffer solution: pOH = pK_b + log₁₀ \(\frac { [salt] }{ [acid] }\)

→ PK_a = – log₁₀ K_a; pK_b = – log₁₀ K_b

→ Solubility product:

k_sp = (xs)^x (ys)^y = x^xy^y x (S)^x+y

By going through these Maharashtra State Board 12th Science Chemistry Notes Chapter 2 Solutions students can recall all the concepts quickly.

Maharashtra State Board 12th Chemistry Notes Chapter 2 Solutions

→ Henry’s law : S = K_HP

→ Raoult’s law : P_soln = x₁P₀

→ Mole fractions, x₁ + x₂ = 1

→ P_soln = P°₁x₁ + P°₂x₂

→ P_soln = (P°₂ – P°₁)x₂ + P°₁

→ Mole fractions of components in vapour phase : y₁ = \(\frac{x_{1} P_{1}^{0}}{P}\) and y₂ = \(\frac{x_{2} P_{2}^{0}}{P}\)

→ For ideal solutions : ΔV_mix = 0; Δ_mixH = 0

→ Relative lowering of vapour pressure = \(\frac{P^{0}-P}{P^{0}}\), x₂ = \(\frac{P^{0}-P}{P^{0}}\)

→ \(\frac{P^{0}-P}{P^{0}}=\frac{W_{2} \times M_{1}}{W_{1} \times M_{2}}\)

→ Δ T_b = K_b x m and Δ T_f — K_f x m

→ ΔT_b = K_b x \(\frac{W_{2} \times 1000}{W_{1} \times M_{2}}\)

→ ΔT_f = K_f x \(\frac{W_{2} \times 1000}{W_{1} \times M_{2}}\)

→ π = cRT and π = \(\frac{W R T}{M \times V}\)

→ i = \(\frac{Colligative property of electrolyte solution}{Colligative property of nonelectrolyte solution of the same concentration}\)

→ Van’t Hoff factor (i) = \(\frac{\Delta T_{\mathrm{b}(\mathrm{ob})}}{\Delta T_{\mathrm{b}(\mathrm{th})}}=\frac{\Delta P_{(\mathrm{ob})}}{\Delta P_{(\mathrm{th})}}=\frac{\Delta T_{\mathrm{f}(\mathrm{ob})}}{\Delta T_{\mathrm{f}(\mathrm{th})}}=\frac{\pi_{\mathrm{ob}}}{\pi_{\mathrm{th}}}=\frac{M_{\mathrm{th}}}{M_{\mathrm{ob}}}\)

→ Colligative properties considering van’t Hoff factor :

→ α = \(\frac{i-1}{n-1}\) (for dissociation)

By going through these Maharashtra State Board 12th Science Chemistry Notes Chapter 1 Solid State students can recall all the concepts quickly.

Maharashtra State Board 12th Chemistry Notes Chapter 1 Solid State

Solids-

• Crystalline
• Amorphous

Crystalline solids-

• Ionic crystals
• Covalent network crystals
• Molecular crystals
• Metallic crystals

Crystal systems-

• Cubic
• Orthorhombic
• Tetragonal
• Monoclinic
• Rhombohedral
• Triclinic
• Hexagonal

Classification of crystal systems (Bravais lattices) :

Cubic lattice –

1. Simple cubic or primitive
2. Body centred cubic
3. Face centred cubic

Number of atoms in the unit cell :

Packing efficiency :

Number of tetrahedral voids = 2 Number of atoms
Number of octahedral voids = Number of atoms

Relation between radius (r) of an atom and edge length (a) of cubic unit cell

Density of the crystal: p = \(=\frac{n \times M}{a^{3} \times N_{\mathrm{A}}}\)

Defects in solids-

(1) Point defects-

1. Vacancy defects (Schottky defects)
2. Interstitial defects (Frenkel defects)
3. Impurity defects-
   • Substitutional impurity defects
   • Interstitial impurity defects

(2) Nonstoichiometric defects

• Metal deficiency defect
• Metal excess defect

Conducting solids-

• Conductors
• Semiconductors
• Insulators

Semiconductors –

• Intrinsic
• Extrinsic
• n-type
• p-type

Magnetic properties-

• Diamagnetic
• Paramagnetic
• Ferromagnetic

(1) Diamagnetism is due to the presence of all paired electrons in the substance.
(2) Paramagnetism is due to the presence of one or more unpaired electrons in the substance.

By going through these Maharashtra State Board Secretarial Practice 12th Commerce Notes Chapter 3 Issue of Shares students can recall all the concepts quickly.

Maharashtra State Board Class 12 Secretarial Practice Notes Chapter 3 Issue of Shares

→ A joint-stock company can raise its capital by issuing shares, debentures, inviting public deposits, taking loans etc.

→ Share Capital refers to the capital made up out of equity shares and preference shares.

Share Capital can be classified as –

• Authorised or Nominal or Registered Capital
• Issued and Unissued Capital
• Subscribed and Unsubscribed Capital
• Called up and uncalled Capital and Reserve Capital
• Paid up Capital and Calls in Arrears

Company can raise capital by selling shares in the market. Generally it issues –

• Equity shares
• Preference shares.

A company can use the following methods for issues of shares –

• Public Issue
• Fixed price issue method
• book building method
• Initial public offer
• Further public offer
• Rights issue
• Bonus issue
• Employee stock option scheme
• Employee stock purchase scheme
• Stock appreciation rights scheme
• Sweat equity shares
• Private placement

Preferential allotment-

Allotment of Shares:
The Supreme Court has defined allotment as “the appropriation out of the previously unappropriated capital of the company of a certain number of shares to a person.
Thus allotment of shares means allotting shares to an applicant based on the application submitted.

Share Certificate:
It is a registered document issued by a company which is an evidence of ownership of specified number of shares of the company. Share certificate should be issued by the company within two months.

Calls on shares:
Besides the application money and allotment money, if a company demands the balance unpaid amount on shares it is called as calls on shares. It is unpaid money demanded by the company.

Forfeiture of Shares:
If a shareholder fails to pay calls on shares within a certain period, the Board of Directors can forfeit the ownership of a member which is called forfeiture of shares. It is a forceful act by the company. Here membership is terminated by the company.

Surrender of Shares:
Voluntary return of shares by the member to the company for cancellation of shares is called surrender of shares.

Transfer of shares:
Transfer of shares means voluntary transfer of shares by a member of a company in favour of another person against consideration. It is a voluntary activity.

Transmission of shares:
When the shares of a member is automatically transferred to the nominee or legal heir on the death, insolvency or insanity of a member, it is called transmission of shares. It is performed by operation of law.

By going through these Maharashtra State Board Secretarial Practice 12th Commerce Notes Chapter 2 Sources of Corporate Finance students can recall all the concepts quickly.

Maharashtra State Board Class 12 Secretarial Practice Notes Chapter 2 Sources of Corporate Finance

→ No business activity can ever be pursued without financial support.

→ Finance is necessary throughout the activities of promotion, organization, and regular operations of the business.

→ The finance needed by a business organization is termed as ‘Capital’

→ Capital formation is a process of collection of capital from various sources according to the financial plan of the company.

→ The various sources of finance can be divided into owned capital and borrowed capital which may be external or internal.

→ When capital is made available from within the organization, it is an internal source of financing.

→ When capital is raised from outsiders, it is an external source of financing.

→ Owned capital is regarded as permanent capital and borrowed capital is regarded as the temporary capital.

→ The various requirements of finance can be divided into short term (maximum one year) and long term (more than a year maybe 5,10,15 years).

→ There are various methods of raising finance namely shares, debentures, bonds, retained earnings/profits, public deposits, trade credit, bank credit, ADR (American Deposit Receipts), and GDR (Global Depository Receipts)

→ A share is a small unit of the share capital of a company.

→ They may be issued at par, premium, or discount and redeemed at par or premium.

→ Equity shares do not enjoy a preference for dividends and do not have priority for payment of capital at the time of winding up of a company.

→ Equity shareholders are risk-takers and hence they are the real owners of the company.

→ Preference shares have prior right to receive a fixed rate of dividend and return of capital in the event of winding up of the company

→ Preference shareholders are cautious investors.

→ They neither take part in management nor attend the meetings and vote on resolutions.

→ They can have class meetings if their rights are to be altered or have not received dividends for more than two consecutive years.

→ The debt acknowledged by a company by issuing a debenture certificate is called a debenture.

→ Debenture holders are creditors of the company.

→ They get fixed interest as a return on their investment.

→ A bond is an instrument issued by the government or business as evidence of debt.

→ Bondholders are creditors of the company.

→ They get fixed interest as returns on their investment regularly or as per terms agreed.

→ Retained earnings is the sum total of accumulated profit that is re-invested in the business.

→ It is a cost-effective method of raising funds and is also known as self-financing/ploughing back of profits/
capitalization of Reserves.

→ A public deposit is a collateral-free loan accepted by public companies for a short period of time ranging from 6
months to 36 months.

→ The company can raise loans from banks in the form of overdraft, cash credit, cash loans discounting of bills. etc.

→ Financial institutions provide financial aid and assistance to companies.

→ Trade credit is a credit extended by manufacturers and suppliers to follow businessmen for 15 days to a
month.

→ Discount is made available if payments are made early.

→ A Bill of exchange is a trade bill that is accepted by the bank and cash is advanced as a loan against it.

→ ADR (American Depository Receipt) and GDR ( Global Depository Receipt) are depository receipts through
which Indian Companies raise equity capital in international markets.