Question

Which of the following is an inner orbital complex as well as diamagnetic in behaviour
[Atomic numbers Zn = 30, Cr = 24, Co = 27, Ni = 28.]
A. `[Zn(NH_(3))_(6)]^(2+)`
B. `[Cr(NH_(3))_(6)]^(3+)`
C. `[Co(NH_(3))_(6)]^(3+)`
D. `[Ni(NH_(3))_(6)]^(2+)`

Answer 1

Correct Answer - C
`[Co(NH_(3))_(6)]^(3+)`
O.N. of `Co= +3`

Due to paired `e^(-)` it is diamagnetic