Question

Dry HCI gas is not acid but it become acidec in presence of water why

Answer 1

Dry Hcl does not contains Hydronium ion so it shows non acidic character but when water is added to it become acidic because on dissolving in water it produces Hydronium ion..

Answer 2

because dry HCL gas has not the presence of hydrogen ions . The acids produce hydrogen ions only on dissolving in water. In absence of water, the HCL gas do not produce hydrogen ions and hence do not show acidic behaviour.