Question

What are the oxidation numbers of `4HNO_3 (aq)`?

So I know hydrogen is +1 and oxygen is -2. Does that make nitrogen +5 or is the coefficient `4` taken into account which would change the oxidation numbers?

Thank you in advance! :)

Answer 1

You got it mate....

Explanation:

Oxidation number is an exercise in simple arithmetic, and of course it is a convenient fiction. The assignment of oxidation number is often useful when we do redox equations. Now the sum of the oxidation numbers is ALWAYS EQUAL to the charge on the ion or the molecule.

Here, we gots `HNO_3`, a neutral molecule. The oxidation number of `O` is GENERALLY `-II` in its compounds and it is here...and the oxidation number of `H` is GENERALLY `+I` in its compounds and it is here...

and so `0=(+I)+(3xx-II)+N_"oxidation number"`

`N_"oxidation number"=+V`

In the context of the question we gots `4xxstackrel(V+)N`. Happy?

What is the oxidation number of `S` in `H_2SO_4`? What about `Cl` in `HClO_4`?