• # question_answer ${{[Ni{{(CN)}_{4}}]}^{2+}}$ and ${{[NiC{{l}_{4}}]}^{2-}}$ have dissimilarity but not in A)  magnetic momentB)  co-ordination number and oxidation statesC)  structureD)  colour

In ${{[Ni{{(CN)}_{4}}]}^{2-}}$ the hybridisation of $Ni$ is $ds{{p}^{2}}$(square planar) having no unpaired electron while in ${{[NiC{{l}_{4}}]}^{-}}\,\,Ni$ is present in $s{{p}^{3}}$hybridisation (tetrahedral) with 2 unpaired electrons. Hence these two complexes differ in magnetic moment, structure, and colour but they have similar coordination number (i.e. 4) and oxidation state (i.e. $+2$)