Question

Which of the following complex ions is expected to absorb visible light?
A. (a) `[Zn(NH_3)_6]^(2+)`
B. (b) `[Cr(NH_3)_6]^(3+)`
C. (c) `[Ti(en)_2(NH_3)_2]^(4+)`
D. (d) `[Sc(H_2O)_(3)(NH_3)_3]^(3+)`

Answer 1

Correct Answer - B
`{:(Ti^(4+):3d^(10),,,,),(Cr^(3+):3d^3,,,,),(Zn^(2+):3d^(10),,,,),(Sc^(3+):3d^(0),,,,):}}` Completely filled or empty d-orbitals are colourless.