Nitric acid acts only as an oxidising agent

cbse
redoxreactions

#1

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


#2

(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.
(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.