Ncert Exercises & Solutions

16.24 Can you use soaps and synthetic detergents to check the hardness of water?

Soaps get precipitated in hard water, but not in soft water. Therefore, soaps can be used for checking the hardness of water.

However, synthetic detergents do not get precipitated either in hard water or in soft water.

Therefore, synthetic detergents cannot be used for checking the hardness of water.