), the paper must be with distilled water first so the gas can dissolve and produce ions.
Collect 2-3 drops of the sample in a clean vessel or well plate. litmus paper
Litmus paper only reacts in the presence of water. To test dry gases (like HClcap H cap C l NH3cap N cap H sub 3 ), the paper must be with distilled water
Generally do not change the color of red or blue litmus paper, though dedicated purple litmus paper exists for this purpose. Types of Litmus Paper litmus paper