Question

Why does dry blue litmus not turn red when held in vapours of dry HCl gas. ​

Answer 1

Explanation:

litmus paper changes its colour only when a liquid is applied over it. So , dry HCL gas will not change the colour of the litmus paper.

Answer 2

Answer:

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.