Among the following complexes, the one which shown zero crystal field stabilization energy (CFSE)-

Options

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

Answer

B

Explanation

`H_(2)O`, a weak field ligand is present in `[Fe(H_(2)O)_(6)]^(3+)`. So the electronic configuration of `Fe^(3+)` is `3d^(5):t_(2g)^(3)e_(g)^(2)`.
Hence, `CFSE =3xx(-0.4Delta_(0))+2xx(0-.6Delta_(0))=0.`