Question

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

Answer 1

The dry ammonia gas has no action on litmus paper, but a solution of ammonia in water turns red litmus paper blue.

It is because the solution of ammonia in water actually results in the better formation of some ammonium hydroxide.

When it comes to ammonium hydroxide, it is actually basic in nature as well as turns red litmus blue.

Answer 2

Ammonia is basic is nature.

Dry ammonia does not give rise to OH- ions. So there is no action on litmus paper.

But a solution of ammonia in water releases OH- ions. Thus the litmus paper turns Red litmus to blue.

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