Among the following pairs of complexes, in which case the `Delta_(0)` value is higher for the first one?

Options

A. `[Co(NH_(3))_(6)]^(3+) and [Co(CN)_(6)]^(3-)`
B. `[CoF_(6)]^(3-) and [Co(NH_(3))_(6)]^(3+)`
C. `[Co(H_(2)O)_(6)]^(2+) and [Co(H_(2)O)_(6)]^(3+)`
D. `[Rh(H_(2)O)_(6)]^(3+) and [Co(H_(2)O_(6)]^(3+)`

Answer

D

Explanation

In complexes `[Rh(H_(2)O)_(6)]^(3+) and [Co(H_(2)O)_6]^(3+)` , central metal cations have same oxidation state as well as same ligands and they fall in same group, but `Delta_(0)` of `[Rh(H_(2)O)_(6)]^(3+) gt Delta_(0)` of `[Co(H_(2)O)_(6)]^(3+)` beause `Rh^(3+)` ha high `Z_(ef f)` value than `CO^(3+)`.