Question

Which of the following has a square planar geometry? .
A. `|PtCl_(4)|^(2-)`
B. `CoCl_(4)|^(2-)`
C. `|FeCl_(4)|^(2-)`
D. `|NiCl_(4)|^(2-)`

Answer 1

Correct Answer - A
Ni , Pd and Pt lie in group 10. Their `M^(2+)` ions have the configuration `(n-1)d^(8)` e.g. `Pt^(2+)` is `5d^(8)`. As we move from 3d to 4d to 5d elements , CFSE increases. Therefore , 5d elements have greater tendency to form low spin complexes, i.e. 5d electrons pair up as follows

Hence hybridization is `dsp^(2)` and it forms spuare planar complex .