Question

dry ammonia has no action on litmus paper but a solutions of ammonia in water turns red litmus paper blue .why is it so?

Answer 1

Dry ammonia does not contain OH - ions so id does not have any effect on red litmus paper. Ammonia reacts with water to form ammonium hydroxide. Ammonium hydroxide is a base and hence it turns red litmus blue.

Answer 2

Answer:

Dry ammonia has no action on litmus paper because it doesn't contain separate H+ ions whereas solution of ammonia in water turns red litmus paper to blue because it contains H+ ions. H+ ions disassociate only in aqueous solution.