1512Every Day ScienceMedium
Permanent hardness of water is due to the presence of __________?
ACalcium sulfate
BSodium bicarbonate
CNone of these
DCalcium bicarbonate
Correct answer
A. Calcium sulfate
Explanation
Permanent hardness of water is due to the presence of Calcium sulfate. Permanent hardness is hardness (mineral content) that cannot be removed by boiling. When this is the case, it is usually caused by the presence of calcium sulfate and/or magnesium sulfates in the water, which do not precipitate out as the temperature increases.