Comproportionation Reaction
A redox reaction in which two species of the same element in different oxidation states combine to give a single intermediate state.
Formula / equation
A⁺ + A⁻ → 2A
Unit
Dimensionless
In depth
The exact reverse of disproportionation, comproportionation is favoured whenever the intermediate oxidation state is the thermodynamically stable one. It is exploited synthetically to prepare a specific oxidation state cleanly without over-reduction or over-oxidation.
Examples in the real world
5I⁻ + IO₃⁻ + 6H⁺ → 3I₂ + 3H₂O, in which iodine at −1 and +5 meets at 0.