Comproportionation

[1] In electrochemistry, the tendency of two redox species to disproportionate, or comproportionate, can be determined by examining their Frost diagram.

The Gibbs free energy ΔG° is related to the reduction potential E° by the formula: ΔG° = −nFE° or nE° = −ΔG°/F, where n is the number of transferred electrons, and F is the Faraday constant (F = 96,485 J/(V·mol) = 96,485 Coulomb).

Non-adjacent neighboring species of Mn obeying the same general rule will also react together as, e.g., Mn2+ and MnO−4 to form MnO2.

The comproportionation reaction cannot easily occur in solids in which the potentially reactive species are immobile and thus cannot react together, or the reaction will be extremely slow and will also require high temperature close to the melting point of the solid to render the reactive species more mobile.

However, if these species are soluble, and thus highly mobile in an aqueous solution, they will much more easily encounter, react and undergo comproportionation.