Permanent harness of water is due to the presence of
-
calcium bicarbonate
-
magnesium bicarbonate
-
calcium sulphate
-
sodium bicarbonate
C
Correct answer
Explanation
Permanent hardness of water is caused by the presence of dissolved chlorides and sulphates of calcium and magnesium. Calcium sulphate is a primary contributor to this condition, which cannot be removed by simple boiling. In contrast, bicarbonates cause temporary hardness.