Write the balanced equation for the reaction between ammonia and sulphuric acid.

Give reason for the following: Liquid ammonia is used as a refrigerant in ice plains.

Give reason for the following: Aqueous solution of ammonia is used for removing grease stains from woollen clothes.

Give reason for the following: Aqueous solution of ammonia gives a pungent smell.

Ammonia solution in water gives a blue precipitate when it combines with a solution of copper salt. The blue precipitate further dissolves in excess of ammonia solution to give an azure blue solution. Explain with equation.