Question

Nitric acid acts only an oxidising agent while nitrous acid acts both as an oxidising as well as reducing agent. Explain.

Answer 1

There are 5 electrons in valence shell of N so it can either gain 3(-3 oxidation state) electron or at most loose 5(+5 oxidation state) electrons to gain the octet of electron.In nitric acid oxidation state of N is +5 which is maximum hence it can gain the electrons only and can be oxidizing agent. while in nitrous acid oxidation state of N is +3 so it can gain or loose electron hence can be oxidant or reductant both.