Comproportionation or symproportionation is a chemical reaction where two reactants containing the same element but with different oxidation numbers, form a compound having an intermediate oxidation number. It is the opposite of disproportionation.
Frost diagrams
thumb|[[Frost diagram for manganese]]
In electrochemistry, the tendency of two redox species to disproportionate, or comproportionate, can be determined by examining their Frost diagram. It is a graphical plot of as a function of the oxidation number for the different redox species of a given element.
The Gibbs free energy ΔG° is related to the reduction potential E° by the formula: or , where n is the number of transferred electrons, and F is the Faraday constant ).
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