Question

In the neighbourhood of your school, hard water required for an experiment is not available. Select from the following group of salts available in your school, a group each member of which, if dissolved in distilled water, will make it hard:

(a) Sodium chloride, calcium chloride

(b) Potassium chloride, sodium chloride

(c) Sodium chloride, magnesium chloride

(d) Calcium chloride, magnesium chloride

Answer 1

(d) Dissolving chloride salts of calcium or magnesium in distilled water will make the water hard, and lather formation will take place with difficulty.