The number of unpaired electrons in the complex ion `[CoF_6]^(3-)` is (Atomic no. of `Co=27`)

Options

A. 3
B. 2
C. 4
D. 0

Answer

C

Explanation

In complex ion `[CoF_(6)]^(3-)` , the oxidation state of cobalt is `+3` . `Co(3d^(7) 4s^(2)) implies Co^(2+) (3d^(6))`
Since `F^(-)` is a weak field ligand, there is no paioring of electrons. Thus, all the electons of `d^(6)` configuration remain unpaired.