A sample of hard water forms yellow stain on the clothes when used for washing . The salts causing yellow stain on the clothes are salts of

A] Fes

B]Ca

C]Mg

D]Na

Calcium and magnesium are usually the minerals that make water hard. The greater the concentration of these minerals, the harder the water. Hard water doesn't clean as effectively as soft water. In hard water much of the detergent added to the washer goes to soften the water instead of to clean the clothes. This means that more detergent must be used than in soft water. Softening water by using more detergent has two drawbacks; it is expensive and if the detergent contains phosphate it can add to water pollution. Heavy duty liquid detergents will remove soil in hard water almost as effectively as powdered phosphate-built detergents and they do not contribute to water pollution. Non-phosphate powdered detergents and soap do not perform satisfactorily in hard water.