Question -
Answer -
Temporary hardness ofwater is due to the presence of bicarbonates of calcium and magnesium in wateri.e., Ca(HCO3)2 and Mg(HCO3) in water. Permanent hardness of water is due tothe presence of soluble chlorides and sulphates of calcium and magnesium i.e.,CaCl2, CaS04, MgCl2 and MgS04.