question_answer

The number of unpaired electrons in tetrahedral \[[Ni{{(CO)}_{4}}]\] is

A)  0     

B)  2     

C)  3     

D)  4

Correct Answer: A

Solution :

In \[[Ni{{(CO)}_{4}}]\], Ni is present as Ni atom. \[Ni=[Ar]\,3{{d}^{8}}4{{s}^{2}}\] CO, being a strong field ligand, transfers the 4s-electrons into 3d-orbitals. \[[Ni{{(CO)}_{4}}]=[Ar]\] Thus, \[[Ni{{(CO)}_{4}}]\]does not contain any unpaired electron.