How is common salt prepared from sea water?

CBSE Class 10
1

(a) How is common salt prepared from sea water?
(b) What will be the approximate pH of the aqueous solutions of the following salts :
(i) Sodium chloride
(ii) Ammonium Chloride

2

(a) Common salt is obtained from sea-water by the process of evaporation. Sea water is trapped in large, shallow pools and allowed to stand there. The sun’s heat evaporates the water slowly and common salt is left behind. This impure common salt obtained has impurities and is hence purified to obtain pure common salt by recrystallization.
(b)
(i) 7
(ii) less than 7