Which of the following complex ions is expected to absorb visible light?

Options

A. `[Sc(H_(2)O)_(3) (NH_(3))_(3)]^(3+)`
B. `[Ti(en)_(2) (NH_(3))_(2)]^(4+)`
C. `[Cr(NH_(3))_(6)]^(3+)`
D. `[Zn(NH_(3))_(6)]^(2+)`

Answer

C

Explanation

`[Cr(NH_(3))_(6)]^(3+)=[Ar]3d^(3)`
Hybridisation is `d^(2)sp^(3)`

Since, `[Cr(NH_(3))_(6)]^(3+)` has three unpaired electrons that.s why it absorbs visible light. All of other complex ion does not have unpaired electrons. That.s why it abosrbs visible light.