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

1 Answer
Aug 16, 2017

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
12Cl2(g)+eCl (i)

Oxidation
12Cl2(g)+6HOClO3+5e+3H2O (ii)

And 5×(i)+(ii) gives:

3Cl2(g)+6HO5Cl+ClO3+3H2O

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.