Question

In the presence of light, nitric acid turns yellowish . Give reason.

Answer 1

Definition of decomposition reaction.

A reaction in which a compound breakdown into 2 or more simpler substance is called decomposition reaction .

• In the presence of light nitric acid undergoes decomposition .
• $4{\mathrm{HNO}}_3\left(\mathrm{aq}\right)\stackrel{\mathrm{light}}{\to }4{\mathrm{NO}}_2\left(\mathrm{g}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)$
• A brown coloured gas is evolved.
• This gas is due to formation of $N{O}_2$
• When $N{O}_2$ dissolves in nitric acid , it turns to yellow.