Question

Dry ammonia has no action on litmus paper,but a solution in water turns red litmus paper blue.Why is it so?

Answer 1

Dry ammonia does not contain OH, so it 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

bcoz the reaction takes place only in the presence of water