Question

why soap donot given proper cleaning action in hard water where as detergent give proper cleaning action explain

Answer 1

Because soap is made up of Sodium and potassium salts whereas the hard water contains calcium and magnesium ions, when soap reacts with these ions of hard water, it forms an insoluble precipitate . For proper cleaning of clothes foam is necessary for removing dirt from clothes. And soaps do not form foam.

Detergents are the Sodium salts of long chain benzene sulphonic acid which has cleansing properties in hard water also. Detergents can form lather well in hard water because they do not form insoluble on reacting with ions of calcium and magnesium present in hard water.