What is meant by 'disproportionation' of an oxidation state ? Give an example.

Explanation

When a particular oxidation state of an element becomes less stable relative to other oxidation states (one lower and one higher) of the same element, then the element in the given oxidation state undergoes simultaneous oxidation and reduction to form two different species containing lower and higher oxidation states of the element. This is called disproportionation of an oxidation state. For example, Cu(I) - compounds are unstable in aqueous solution and undergo disproportionation to form metallic copper Cu (0) and Cu (II) compound. `2Cu^(+)(aq)to Cu^(2+)(aq)+Cu(s)`