Of the following complex ions, which is diamagnetic in natures?

Options

A. `[CoF_(3)]^(3-)`
B. `[NiCI_(4)]^(2-)`
C. `[Ni(CN)_(4)]^(2-)`
D. `[CuCI_(4)]^(2-)`

Answer

C

Explanation

`[CoF_(6)]^(3-)` , no rerrangement as `F^(-)` is a weak field ligand

`[NiC1_(4)]^(2-)` , no rearrangement as `C1^(-)` is a weak field ligand

`[Ni(CN)_(4)]^(2-)` , rearrnangement as `CN^(-)` is a strong field ligand

`[CuC1_(4)]^(2-)` , no rearrangement as `C1^(-)` is a weak field ligand