The complex with maximum magnetic in the following is :

Options

A. `[CoF_(6)]^(3-)`
B. `[Co(NH_(3))_(6)]^(3+)`
C. `[Ni(NH_(3))_(4)]^(2+)`
D. `[Ni(CN)_(4)]^(2-)`

Answer

A

Explanation

Since `F^(-)` ions are weak field lifands, they cannot cause any electron pairing `(Co^(3+)` ) ion is the complex has `3d^(8)` configuration with four unpaired electrons. The complex is expected to be maximum paramagnetic in nature. All other complexes are of diamagnetic nature since the liagads are strong ligands.