from the information given in the passage what is the most likely configuration of the cobalt d-electrons for the species `(A)` `CoCl_(6)^(3-)` and `(B)Co(No_(2))_(6)^(3-)` ?
(a) both `(A)` and (B)` has low spin (b) both `(A)` and (B)` has low spin (c) both `(A)` and (B)` has low spin (d) both `(A)` and (B)` has low spin .

Answer

b

Explanation

`CI^(Θ)` always behaves as weak field ligand so high spin complex formed Also here `Delta_(0)` is not sufficient to overcome pairing energey `P,NO_(2)` with `Co` behaves as strong field ligand and hence low spin complex Also `Delta_(0)gtP` and hence pairing takes place .