Ferric iodide is very unstable but ferric chloride is stable. Explain.

Explanation

Iodide ion `(I^(-))` is a strong reducing agent and reduces `Fe^(3+)` ion to `Fe^(2+)` ion. Therefore, ferric iodide `(FeI_(3))` does not exist while ferrous iodide `(FeI_(2))` does exist. On the other hand, chloride ion `(Cl^(-))` being a weak reducing agent cannot reduce `Fe^(3+)` ion. As a result, ferric chloride `(FeCl_(3))` is quite stable.