Why does dry HCl gas not change the color of the dry litmus paper?
HCl Gas Affects The Color Of Dry Litmus Paper
Dry HCl acts as a gas – hydrogen chloride. It does not act as an acid until present in an aqueous medium; that is, an acid can show acidic behaviour only in the presence of Protons (H+ ions). In the presence of an aqueous medium, the acid dissociates into H+ ions, which contribute to its acidic behavior. The colour change of litmus paper from blue to red is characteristic of acids, but in the absence of water, it will not show the acidic properties. An acid requires water to show its properties.
– Written by Manpreet
