Which of the following complex ions is most stable ?

Options

A. `[Co(H_(2)O)_(6)]^(3+)`
B. `[CO(CN)_(6)]^(3-)`
C. `[CO(C_(2)O_(4))_(3)]^(3-)`
D. `[COF_(6)]^(3-)`

Answer

C

Explanation

Stability of the complex ion depends upon the chelation. More is the number of chelating rings more will be the stability of complex ion. Among the given complex ion `C_(2)O_(4)^(2-)` is a bidentate ligand and thus forms chelation and will be must stable .
`o x = C_(2) O_(4) [CO(C_(2)O_(4))_(3) ]^(2-)`