A gas is produced when cone. H2S04 is added to solid sodium chloride taken in a test tube. The gas coming out through the delivery tube is passed over a dry blue litmus paper and then over a moist blue litmus paper. Record your observations and explain reason with the help of chemical equation.
HCl gas is produced.
When the gas is passed through dry litmus paper, there is no change in colour because it cannot show acidic properties, as H+ ions are not present.
When the gas is passed through moist blue litmus paper, colour changes to red as it shows acidic properties. It happens because H+ ions are produced when HCl dissolves in water.