Question

Hard water required for an experiment is not available in a school laboratory. However, following salts are available in the laboratory. Select the salts which may be dissolved in water to make it hard for the experiment. (1)
(1)
Calcium Sulphate
(2)
Sodium Sulphate
(3)
Calcium Chloride
(4)
Potassium Sulphate
(5)
Sodium Hydrogen Carbonate
(6)
Magnesium Chloride
(A) 1, 2 and 4
(B) 1, 3 and 6
(C) 3, 5 and 6
(D) 2, 4 and 5

Answer 1

Answer:

c)3,5 and 6✔✔✔✔

Follow me ⭐⭐⭐

Answer 2

(C) 3, 5 and 6

Explanation:

Hard water is nothing but water containing salts of calcium and magnesium, principally as bicarbonates, chlorides or sulphates. Hardness caused by calcium bicarbonate is temporary, as boiling converts the bicarbonate to the insoluble carbonate. Hardness from the other salts are permanent.

If hard water is not available in the laboratory, the student can make it by dissolving Calcium Chloride or Magnesium chloride in a beaker of water.