- Which acid produces brown fumes on heating ?;
- Which gas is evolved by the reaction of common salt with concentrated H2SO4 ?
The acid that produces brown fumes on heating is nitric acid (HNO3). This is due to the decomposition of the acid into nitrogen dioxide (NO2) gas, which has a brown colour.
The gas evolved by the reaction of common salt (NaCl) with concentrated H2SO4 is hydrogen chloride (HCl) gas. This is due to the reaction between sodium chloride and sulfuric acid to form hydrogen chloride gas and sodium bisulfate (NaHSO4) salt.