(i) When a glass rod dipped in ammonia, solution is held near the vapours of the acid, it form a dense white fumes of ammonium chloride.
(ii) When hydrochloric acid is treated with silver nitrate solution, it forms curdy white precipitate which is soluble in excess of ammonium hydroxide solution.
(iii) When hydrochloric acid is boiled with manganese dioxide, greenish yellow chlorine gas is evolved.
