Question

(Ni(Co)4) has tetrahydral geometry whereas (Ni(CN)4)2- has square geometry​

Answer 1

Explanation:

Ni(CO)4 = Ni + 4CO

Thus Ni(CO)4 is diamagnetic. thus according to VBT sp3 hybridization have tetrahedral geometry. In [Ni(CN)4]2-, there is Ni2+ ion for which the electronic configuration in the valence shell is 3d8 4s0. In presence of strong field CN- ions, all the electrons are paired up.