Question

The magnetic properties and geometries of $[Ni(CN{)}_4{]}^{2-}$ and $[NiC{l}_4{]}^{2-}$ respectively are

• A. diamagnetic, paramagnetic and tetrahedral, square planar
• B. paramagnetic, diamagnetic and tetrahedral, square planar
• C. paramagnetic, diamagnetic and square planar, tetrahedral
• D. diamagnetic, paramagnetic and square planar, tetrahedral.

Answer 1

Answer: (D)

In $[Ni(CN{)}_4{]}^{2-}$ , due to strong field ligand like $C{N}^{-}$, pairing of electrons takes place and gives diamagnetic and $ds{p}^2$-hybridisation with square planar structure.
In $[NiC{l}_4{]}^{2-},C{l}^{-}$ is a weak field ligand, so does not causes any pairing of electrons and hence gives paramagnetic and $s{p}^3$-hybridisation with tetrahedral structure.