Question

The oxidation state of Oxygen in $K{O}_2$ is .

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

Answer 1

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

We know that the sum of oxidation numbers of all the elements in a compound is equal to 0.
Here the oxidation number of K (Potassium) is +1. So, let the oxidation number of O (oxygen) be $x$.
If the sum of oxidation numbers of this compound is equal to 0. We get the equation as
$+1+2\times x=0$
$2\times x=-1$
Hence the oxidation number of O (oxygen) is -1/2 or -0.5