Conc. \(\mathrm{HNO}_3\) turns brown on standing due to formation of
Conc. \(\mathrm{HNO}_3\) turns brown on standing due to formation of
NO
\(\mathrm{NO}_2\)
\(\mathrm{N}_2 \mathrm{O}\)
\(\mathrm{N}_2 \mathrm{O}_4\)
Solution
The decomposition of \(\mathrm{HNO}_3\) is represented by the equation.
\(4 \mathrm{HNO}_3 \longrightarrow 2 \mathrm{H}_2 \mathrm{O}+4 \mathrm{NO}_2+\mathrm{O}_2\)
Due to the formation of nitrogen dioxide, it turns yellow brown. Hence, option (b) is correct.