Question

Oxidation state of oxygen in ${KO}_2$ is :

• A. $0$
• B. $-1$
• C. $-\frac{1}{2}$
• D. $-2$

Answer 1

The correct option is C $-\frac{1}{2}$

It has only one electron in its valence shell and can only take the +1 oxidation state.

Now, in $K{O}_2$, let oxidation number of oxygen be x.

Therefore, $1+2x=0$ as $K=+1$ and $K{O}_2$ is a neutral molecule.

The oxidation number of oxygen in $K{O}_2$ is $\frac{-1}{2}$