Chemistry - Coordination Chemistry Question with Solution | TestHub

The statement in option D is false. Bis(dimethylglyoximato)nickel(II) is a diamagnetic, square planar complex, not tetrahedral. This is due to strong field ligand DMG forming a low-spin $d^8$ complex.

A. Correct. $\mathrm{NiC}{\mathrm{l}}_4^{2-}$ is tetrahedral, paramagnetic ($d^8$, weak field). $\mathrm{PtC}{\mathrm{l}}_4^{2-}$ is square planar, diamagnetic ($d^8$, strong field).

B. Correct. $\mathrm{Co}{\mathrm{F}}_6^{3-}$ is paramagnetic ($d^6$, high spin). $\mathrm{Ni}{\mathrm{F}}_6^{2-}$ is diamagnetic ($d^8$, low spin).

C. Correct. Crystal field splitting energy ${\Delta }_o$ increases with ligand strength: $\mathrm{C}{\mathrm{l}}^{-}$ (weak) < $\mathrm{N}{\mathrm{H}}_3$ (medium) < $\mathrm{C}{\mathrm{N}}^{-}$ (strong).