Question

State reason for dry hydrogen chloride gas do not turn blue litmus red whereas dillute hydrochloric acid does

Answer 1

Because acids in their dry state show different properties.In dry state, there are no water molecules to form Hydronium ions(H₃O⁺), which gives acids their characteristic properties.

Answer 2

when acid dissolves in water it releases H+ions that is why litmus turns red
dry help doesn't contain any water content so it does not produce h+ ions