Maharashtra Board Class 12 Chemistry Notes Chapter 8 Transition and Inner Transition Elements

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