Question

Among the following, the most stable complex is
(i). `[Fe(H_2O)_6]^(3+)`
(ii). `[Fe(NH_3)_6]^(3+)`
(iii). `[Fe(C_2O_4)_3]^(3-)`
(iv). `[FeCl_6]^(3-)`

Answer 1

In each of the given complex Fe is in +3 oxidation state As `C_(2)O_(4)^(2-)` is didentate chelating ligand it forms chelate rings and hence (iii) out of complexes given above is the most stable complex.