Question

Which of the following statements are true? Rewrite the false statements after correction.
(a) Water which looks clean and sparkling is suitable for drinking.
(b) soap lathers well in soft water.
(c) sodium sulphate is one of the substances which cause hardness in water.
(d) insoluble salts of calcium cause hardness in water.
(e) Rainwater, as it falls, is always pure.

Answer 1

(a) False.
Water that looks clean and sparkling may not be suitable for drinking. It may contain invisible harmful microorganisms in it.

(b) True.

(c) False.
Hardness in water is caused by insoluble salts of calcium and magnesium.

(d) True.

(e) True.