Question

The geometry of ${\left[Ni(CN{)}_4\right]}^{2-}$ and ${\left[NiC{l}_4\right]}^{2-}$ ions are :

• A. tetrahedral
• B. square planar
• C. square planar and tetrahedral respectively
• D. tetrahedral and square planar respectively

Answer 1

Answer: (C)

The geometry of ${\left[Ni(CN{)}_4\right]}^{2-}$ is square planar and ${\left[NiC{l}_4\right]}^{2-}$ is tetrahedral
$Ni=[Ar]3d^{8}4s^2$

$C{N}^{-}$is a strong ligand (crystal field theory) hence it cause the pairing of electron in $N{i}^{2+}$ while $C{l}^{-}$is a weak ligand so it does not cause pairing of electrons