Question

What is the sum of oxidation numbers of all of the atoms in a neutral compound?

Answer 1

Since neutral compounds have no charge, the sum of the oxidation numbers of all the elements in the compound is zero.

The oxidation number for an element expresses the oxidation state of that element.

Let us consider an example: potassium permanganate.

In the first case, potassium permanganate, $KMn{O}_4$, the sum of oxidation number is $0$ (neutral).

$K=+1;Mn=+7;O=-2$

So, sum of oxidation states:

$(+1)+(+7)+4\times (-2)=8-8=0$