Question

The degree of hardness of water is usually expressed in terms of

(a) parts per million by weight of MgSO₄ 

(b) grams per litre of CaCO₃ and MgCO₃ actually present

(c) parts per million by weight of CaCO₃ regardless of whether it is actually present 

(d) parts per million of CaCO₃ actually present in water. 

Answer 1

Correct option (c)

Explanation:

Degree of hardness of water is expressed in terms of parts per million by weight of CaCO₃ equivalent to various calcium and magnesium salts present.