What is the definition of disproportionation in chemical reactions?

Disproportionation is defined as a specific type of redox reaction in which a single substance undergoes both oxidation and reduction simultaneously, resulting in the production of two different products that have different oxidation states. In this process, one part of the substance is oxidized (loses electrons) while another part of the same substance is reduced (gains electrons), leading to the formation of two different products from one reactant.

For instance, in the disproportionation of chlorine gas, Cl2 can be converted into both Cl- (chloride) and ClO3- (chlorate), where chlorine is reduced in one case and oxidized in the other. This dual change in oxidation state exemplifies the fundamental nature of disproportionation reactions, distinguishing them from other types of redox reactions.

The other options do not accurately describe disproportionation. Conversions into two products of the same oxidation state do not reflect the essence of proportionately increased oxidation states within the reactant. Equilibrium between two phases pertains to phase transitions, such as solid-liquid or liquid-gas equilibria, and does not involve changes in oxidation states. Finally, the description of forming a stable compound from a gas relates more to chemical synthesis or physical changes rather than redox