Question

Why hard water does not form later with soap? What advantages has soap over detergents.

Answer 1

Hard water is the term for water with a lot of dissolved calcium and magnesium, the calcium and magnesium reacts with the fatty acids in soap to form an insoluble scum preventing the detergent effect of the soap. When the scum dries on washed clothing it makes them stiff (hence the term hard water) and uncomfortable.

Advantages of soaps over detergents are as follows:-

1. Soaps are made from natural fats and oils so are fully biodegradable hence do not pollute water as compare to detergents.

2. Soap is cheaper and readily available.

3. Soap works well for cleaning of clothes in soft water.