The hybridization and magnetic behaviour of cobalt ion in $\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{6}\right]^{3+}$ complex, respectively is

(C) $\mathrm{d}^{2} \mathrm{sp}^{3}$ and diamagnetic

(A) $\mathrm{sp}^{3} \mathrm{~d}^{2}$ and diamagnetic

(B) $\mathrm{d}^{2} \mathrm{sp}^{3}$ and paramagnetic

(D) $\mathrm{sp}^{3} \mathrm{~d}^{2}$ and paramagnetic

JEE Main · 2023 · 24 Jan 2023 · Shift 2 · Coordination Compounds

The hybridization and magnetic behaviour of cobalt ion in

[Co (NH_{3})_{6}]^{3 +}

complex, respectively is

(A) $sp^{3} d^{2}$ and diamagnetic
(B) $d^{2} sp^{3}$ and paramagnetic
(C) $d^{2} sp^{3}$ and diamagnetic✓ Correct
(D) $sp^{3} d^{2}$ and paramagnetic

Answer: (C)

Solution

[Co (NH_{3})_{6}]^{3 +}

the cobalt is in the

+ 3

oxidation state, which gives it a

3 d^{6}

configuration with an empty

4 s

. Ammonia is a strong field ligand, so it forces the six

d

electrons to pair up and vacates two of the inner

3 d

orbitals. These two

3 d

orbitals, together with the

4 s

and the three

4 p

orbitals, undergo

d^{2} s p^{3}

hybridisation to receive the six lone pairs from the ligands. Since every electron is now paired the net magnetic moment is zero, so the complex is an inner-orbital, diamagnetic species with

d^{2} s p^{3}

hybridisation.

JEE Main · 2023 · 24 Jan 2023 · Shift 2 · Single correct option

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JEE Main · 2023 · 24 Jan 2023 · Shift 2 · Coordination Compounds

Solution

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