Give reasons for the following :
(a) Liquid ammonia is used as a refrigerant in ice plants.
(b) Aqueous solution of ammonia is used for removing grease stains from woollen clothes.
(c) Aqueous solution of ammonia gives a pungent smell.
(d) Aqueous solution of ammonia conducts electricity.
Ammonia is a brown coloured, pungent smelling gas with slight sour taste.
