Give the chemical reaction to support that `+5` oxidation state of `Bi` is less stable than `+3` state.

Explanation

Due to inert pair effect, Bi can show +3 and +5 oxidation states. Since the inert pair effect is maximum in case of Bi, therefore, its +5 oxidation state is less stable than +3 oxidation state. This is evident from the observation that `BiCI_(3)` even on prolonged heating with `CI_(2)` does not form `BiCI_(5)`