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 ?
Ammonia in water forms ammonium hydroxide. These hydroxide ions turns red litmus blue.
Ammonia is a brown coloured, pungent-smelling gas which turns moist blue litmus paper into the red colour.
What would you observe when :
(a) blue litmus is introduced into a solution of hydrogen chloride gas,
(b) red litmus paper is introduced into a solution of ammonia in water,
(c) red litmus paper is introduced in caustic soda solution?