<prompt> Temporary hardness of water is primarily due to the presence of:Calcium and magnesium sulphatesCalcium and magnesium chloridesCalcium and magnesium bicarbonatesCalcium and magnesium nitrates  <response>: HARDNESS OF WATER Hardness of water is defined as the soap destroying power of water Hardness of water is of two types Types of hardness Underlying causes Temporary hardness carbonate hardness Calcium magnesium salts of bicarbonates Permanent hardness non - carbonate hardness Calcium magnesium salts of sulfates chlorides nitrates Hardness of water is expressed in terms of milliequalents per litre meqL of calcium carbonate CaCO3 1 meqL hardness 50 mg CaCo3 50 ppm per litre of water Softening of drinking water is done if hardness is 150 mgL 