40ᵗʰ B.P.S.C. (Pre) 1995
Permanent hardness of water is due to –
aChlorides and sulphates of Calcium and Magnesium✓ Correct
bCalcium bicarbonate sulphates
cMagnesium bicarbonate
dChlorides of Silver and Potassium
Explanation
Hard water is water that does not produce lather easily when detergent (soap) is used. The main cause of this is the presence of chlorides and sulphates of calcium and magnesium. The Fertilizers
general-science