Question

In which of the following cordination entities, the magnitude of `Delta_(0)[CFSE` in octahedral field] will be maximum ?
A. `[Co(H_(2)O)_(6)]^(3+)`
B. `[Co(NH_(3))_(6)]^(3+)`
C. `[Co(CN)_(6)]^(3-)`
D. `[Co(C_(2)O_(4))_(3)]^(3-)`

Answer 1

Correct Answer - 3
As in all the given complex the central metal atom is same and contains same number of d electrons, thus CFSE is decided by ligands . In case of strong ligand, CFSE is maximum. `CN^(-)` is a strong field ligand, Hence, in `[Co(CN)_(8)]^(3-)`CFSE is maximum