Crystal field theory provides correct electronic distribution of central metal under surrounding ligannd field, hence it clearly explains magnetic moment, colour of a complex.
Q. Which of the following hydrated complex ion has high intensity colour in aqueous solution.

Options

A. `[Mn(H_(2)O)_(6)]^(3+)`
B. `[Co(H_(2)O)_(6)]^(2+)`
C. `[Ni(H_(2)O)_(6)]^(2+)`
D. `[Mn(H_(20O)_(6)]^(2+)`

Answer

A

Explanation

In `[Mn(H_(2)O)_(6)]^(3+)`: Both selection rules are followd due to unsymmetrical filling of `e_(g)` set of orbitals.