Question

explain the formation of scum when hard water is treated with soap​

Answer 1

Answer:

Hard water often contains salts of calcium and magnesium. Soap molecules react with the salts of calcium and magnesium and form a precipitate. This precipitate begins floating as an off-white layer over water. This layer is called scum. Soaps lose their cleansing property in hard water because of formation of scum.

Answer 2

Explanation:

hard water contains calcium and magnesium and soap is basically sodium or potassium salt of higher fatty acids when soap is added to hard water corresponding calcium and magnesium salts are formed which being in soluble that dissipated this precipitated second is come reaction taking place