Question

Both [Ni (CO)₄] and [Ni (CN)₄]²⁻ are diamagnetic.
The hybridisations of nickel in these complexes, respectively, are
(a) sp³, sp³ (b) sp³, dsp²
(c) dsp², sp³ (d) dsp², sp²

Answer 1

(b) sp³, dsp²

Explanation:

The hybridization of nickel in both these complexes, respectively, are sp3 and dsp2.

1. The oxidation state of Nickel is 0 in complex 1 and +2 in complex 2.
2. Nickel has a (d10) configuration in complex 1 and (d8) configuration in the complex 2.
3. CN- is a strong electron donor, so it enables pairing and therefore complex 2 has a dsp2 hybridization, while complex 1 has no empty d orbitals, so has to have a sp3 hybridization.

Option B is the answer.