Question

Give two chemical tests for nitric acid.

Answer 1

Two chemical tests for nitric acid:

1. On heating nitric acid, brown fumes of nitrogen dioxide are formed.
$4{\mathrm{HNO}}_3\stackrel{∆}{\to }2{\mathrm{H}}_2\mathrm{O}+4{\mathrm{NO}}_2+{\mathrm{O}}_2$

2. On heating concentrated nitric acid with copper turnings, brown fumes of nitrogen dioxide are given off.

$\mathrm{Cu}+4{\mathrm{HNO}}_3\stackrel{∆}{\to }\mathrm{Cu}{\left({\mathrm{NO}}_3\right)}_2+2{\mathrm{NO}}_2+2{\mathrm{H}}_2\mathrm{O}$