question_answer

The complex showing a spin-only magnetic moment of 2.82 B.M. is:

A) \[Ni{{\left( CO \right)}_{4}}\]                 

B) \[{{[NiC{{l}_{4}}]}^{2-}}\]

C) \[Ni{{\left( PP{{h}_{3}} \right)}_{4}}\]              

D) \[{{[Ni{{(CN)}_{4}}]}^{2-}}\]

Correct Answer: B

Solution :

[b] \[{{\left[ NiC{{l}_{4}} \right]}^{2-}},O.S.of\,Ni=+2\] \[Ni(28)=3{{d}^{8}}4{{s}^{2}}\] \[C{{l}^{-}}\] being weak ligand it cannot pair up the two electrons present in 3d orbital No. of unpaired electrons = 2 Magnetic moment, \[\mu =2.82\text{ }BM.\]