In the laboratory preparation of nitric acid, nitre is heated with :
conc. H2SO4
Reason — In the laboratory preparation of Nitric acid by distillation process, potassium nitrate (nitre) is heated with conc. sulphuric acid (H2SO4).
KNO3[conc.]+H2SO4[conc.]→<200°CKHSO4[acid salt]+HNO3\underset{[\text{conc.}]}{\text{KNO}_3} + \underset{[\text{conc.}]}{\text{H}_2\text{SO}_4} \xrightarrow{\lt 200 \degree\text{C}} \underset{[\text{acid salt}]}{\text{KHSO}_4} + \text{HNO}_3[conc.]KNO3+[conc.]H2SO4<200°C[acid salt]KHSO4+HNO3
