Question

The oxidation number of oxygen in $K{O}_2$ is:

• A. $-2$
• B. $-1$
• C. $-\frac{1}{2}$
• D. $-\frac{1}{3}$

Answer 1

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

Let $x$ be the oxidation number of oxygen in potassium super oxide $\left(K{O}_2\right)$.
The oxidation number of potassium is $+1$.
In the neutral molecule, the sum of the oxidation number is $0$.
$1+2\left(x\right)=0$ or, $x=-\frac{1}{2}$.