Question

Dry HCL gas does not change the colour of blue Litmus Paper give reasons

Answer 1

because acid show their acedic character in presence of H2O.in which hydrogen (h+)ion is present .so dry litmus paper doesn't change the colour of blue litmus paper

Answer 2

We know that the colour of litmus paper is changed by H + ions because of acid.

Dry HCL it does not dissociate to give H+ ions.

Acids dissociate to give ions only in the aqueous solution.

In this HCL is not in aqueous form nor litmus paper is wet, so the colour of litmus paper does not change.