Question

$H_2{O}_2+H_2{O}_2\to 2H_{2}O+O_2$ is an example of dispropotionation reaction because :

• A. oxidation number of oxygen only decreases
• B. oxidation number of oxygen only increases
• C. oxidation number of oxygen decreases as well as increases
• D. oxidation number of oxygen neither decreases nor increases

Answer 1

The correct option is C oxidation number of oxygen decreases as well as increases

The disproportionation reaction is a reaction in which a substance is simultaneously oxidized and reduced giving two different products.
$H_2{O}_2+H_2{O}_2\to 2H_{2}O+O_2$ is an example of disproportionation reaction because oxidation number of oxygen decreases as well as increases.
The oxidation number of oxygen in $H_2{O}_2$ is $-1$.
The oxidation number of oxygen in $H_{2}O$ is $-2$.
The oxidation number of oxygen in $O_2$ is $0$.
Thus, the oxidation number of oxygen increases from $-1$ (in $H_2{O}_2$) to $0$ (in $O_2$) and decreases from $-1$ (in $H_2{O}_2$) to $-2$ (in $H_{2}O$).