Question

An aqueous solution of a gas (X) turns red litmus blue. When added to excess of copper sulphate solutiory a deep blue colour is obtained. On addition of ferric chloride solution, a deep blue colour is obtained. On addition of ferric chloride solution, a brownish precipitate soluble in HNO3 is obtained. Identify the gas (X) and write equations of the reactions involved.

Answer 1

The data suggests that the gas is ammonia (NH3). In aqueous solution, it forms NH4OH which turns red litmus blue. The reactions taking place in aqueous solution are-