Question

Show oxidizing nature of ${\mathrm{HNO}}_3$.

Answer 1

Oxidizing Agent- The substance(atom, ion or molecule) that gains electrons and is thereby reduced to a low valency state is called an oxidizing agent.
Oxidizing nature of ${\mathrm{HNO}}_3$- It is a strong oxidizing agent because when nitric acid undergoes decomposition it yields nascent oxygen which is very reactive.
$$\begin{gathered} \underset{\mathrm{cons}.}{2{\mathrm{HNO}}_3}\to {\mathrm{H}}_2\mathrm{O}+2{\mathrm{NO}}_2+\underset{\mathrm{nascent}\mathrm{Oxygen}}{\left[\mathrm{O}\right]} \\ \underset{\mathrm{dil}.}{2{\mathrm{HNO}}_3}\to {\mathrm{H}}_2\mathrm{O}+2\mathrm{NO}+\underset{\mathrm{nascent}\mathrm{Oxygen}}{3\left[\mathrm{O}\right]} \end{gathered}$$
This nascent oxygen is very reactive and unstable as a result, it oxidizes metals and non-metals. In this process the oxidation state of nitric acid varies from $+5$to $-3$ so various oxides of nitrogen will be obtained as products $(\mathrm{NO},{\mathrm{NO}}_2,{\mathrm{N}}_2\mathrm{O})$ etc.