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

(i)${{HNO}*{3}}$
Oxidation number of N in ${{HNO}*{3}}$ is + 5.

Maximum oxidation number of N is + 5 because it has five electrons in the valence shell (${{2s}^{2}}$${{2p}^{3}}$)

Minimum oxidation number of N is — 3 because it can accept 3 more electrons to get noble gas configuration. Since oxidation number of N in ${{HNO}

*{3}}$ is maximum, therefore, it can only decrease.*

Thus, ${{HNO}{3}}$ can act as an oxidising agent.

Thus, ${{HNO}

(ii)${{HNO}

*{2}}$*

Oxidation number of N = + 3 Maximum oxidation number of N = + 5 Minimum oxidation number of N = - 3 Therefore, the oxidation number of N can increase by losing electrons or can decrease by accepting electrons. Thus ${{HNO}{2}}$ can act both as an oxidising as well as a reducing agent.

Oxidation number of N = + 3 Maximum oxidation number of N = + 5 Minimum oxidation number of N = - 3 Therefore, the oxidation number of N can increase by losing electrons or can decrease by accepting electrons. Thus ${{HNO}