Question

What is soft water and hard water in chemistry?

Answer 1

Hard water-this is the water that contains an appreciable quantity of dissolved minerals (like calcium and magnesium).
Soft water-this is treated water in which the only ion is sodium.
in other words water tht is free from dissolved minerals of calcium and magnesium

Answer 2

Explanation:

• The water free soluble salts of calcium and magnesium, is called "soft water". It gives lather with soap.

• Presence of calcium and magnesium salts (mainly) and iron salt in the form of hydrogen carbonate, chloride and sulphate in water makes water hard. Hard water does not give lather with soap.

• Temporary hardness is due to the presence of magnesium and calcium hydrogen carbonate in water. It can be removed by boiling and Clark's method.

• Permanent hardness is due to the presence of soluble salts of magnesium and calcium in the form of chlorides and sulphates in water. Permanent hardness can be removed my treating the water with washing soda, Calgon's method, ion - exchange method etc.