Which one of the following is an outer orbital complex and exhibits paramagnetic behaviour ?

Options

A. `[Ni(NH_(3))_(6)]^(2+)`
B. `[Zn(NH_(3))_(6)]^(2+)`
C. `[Cr(NH_(3))_(6)]^(3+)`
D. `[Co(NH_(3))_(6)]^(3+)`

Answer

A

Explanation

In `[Ni(NH_(3))_(6)]^(2+), Ni^(2+)` is `3d^(8)`. Its electronic configuration is

Thus, hybridization is `sp^(3)d^(2)` giving outer orbital complex which is paramagnetic.