Question

How do you solve and represent `"disproportionation reactions"`? Is there an easy way to do this?

Answer 1

Other than by writing separate oxidation and reduction reactions? Not to my knowledge...... And you asked a rather open-ended question.

Explanation:

This is best illustrated by an actual example. Chlorine gas is known to undergo disproportionation in alkaline conditions to give `"chloride"` and `"chlorate ions"`. This is the EXPERIMENTAL result, which must simply be known.

`"Reduction"`
`1/2Cl_2(g) + e^(-) rarr Cl^(-)` `(i)`

`"Oxidation"`
`1/2Cl_2(g) + 6HO^(-) rarr ClO_3^(-)+ 5e^(-) +3H_2O` `(ii)`

And `5xx(i) + (ii)` gives:

`3Cl_2(g) + 6HO^(-) rarr 5Cl^(-) + ClO_3^(-)+3H_2O`

Which is balanced with respect to mass and charge, as is always required. Clearly zerovalent chlorine gas has undergone reduction to chloride ion, and oxidation to chlorate ion; i.e. a disproportionation reaction.