12. Textbook questions VII

  

The precipitate formation of scum is formed when soapfatty aciddetergentsurfactant is used for washing clothes. With hard water, a considerable quantity of soap is destroyed by reacting with the sodiumpotassiumchlorinecalcium and sodimsaltsmagnesiumchlorine ions of hard water to make an insoluble precipitate.

 

The precipitate formed by the action of soft waterpure waterdirt waterhard water on soap sticks to the clothes being washed and interferes with the cleaning capability of the other surfactantfatty aciddetergentsoap. This process makes the cleaning of clothes difficult.