Question

Why soap is not used for washing clothes with Hard water

Answer 1

Although soap is a good cleaning agent, its cleaning capacity is reduced when used in hard water. ... The insoluble scum sticks on the clothes and so the cleaning capacity of soap is reduced. The cleaning action of soap is very effective in soft water because it contains negligible calcium and magnesium ions.

Answer 2

soaps are not suitable for washing clothes when water is hard: Soaps, when used with hard water, does not lather or produce foam easily because of the formation of a curdy precipitate or scum. This scum is created when soaps react with the calcium and magnesium ions present in hard water..