Question

What is the oxidation number of iron in `Fe_2O_3`?

Answer 1

`+3`

Explanation:

So to find out the oxidation number of iron the iron oxide we start of by finding the oxidation number of oxygen and combine them.
So we know that oxygen has a oxidation number of `-2`. Since we have 3 oxygens this would give a total of `-6`.
We know that the charge should be stable `(=0)`, so therefore iron must have a oxidation number of `+3` since `2*3=6`.