Question

Hydrogen peroxide (`H_2O_2`) decomposes to form water and oxygen. How do you write the balanced equation for this reaction?

Answer 1

`2H_2O_2(l) rightleftharpoons 2H_2O(l) + O_2(g)`

Explanation:

This is in fact a disproportionation reaction in that oxygen in peroxide (`-I` oxidation state) has given water (`-II` oxidation state for oxygen) and zerovalent oxygen gas (`0` oxidation state for oxygen).

Often a `Mn^(2+)` salt is added to catalyze this reaction.