Question

How can we tell if a gas is acidic or basic?

Answer 1

Gas can be passed through water and then can be treated with litmus solution. If blue litmus turns to red it is acidic otherwise base. Further non-metal oxides are gaseous in nature. For eg. CO₂. When CO₂ gas combines with water, it forms carbonic acid i.e H₂CO₃. Similarly SO₂ forms H₂SO₃.

Remember that in dry condition even HCl gas doesn’t show acidity as water is required for ionization.