Question

What is meant by the temporary and permanent hardness of water and how it is caused?

Answer 1

Hint :The presence of soluble bicarbonates, chlorides, and calcium and magnesium sulphates causes water to be hard. The mineral content of hard water is high. It is generated when water percolates through the deposits of magnesium and calcium carbonates found in chalk and limestone. It does not lather with soap and is therefore unsuitable for laundry.

Complete Step By Step Answer:
Temporary Hardness of water:
Water becomes temporarily hard due to the presence of magnesium and calcium carbonates. The hardness in the water can be removed in this scenario by boiling it. When we boil water, the soluble $ Mg{\left( {HC{O_3}} \right)_2} $ salts are transformed to insoluble $ Mg{\left( {OH} \right)_2} $ , which precipitates and is eliminated. The water we get after filtering is soft water.
Permanent Hardness of Water:
Permanent hardness is defined as the presence of soluble magnesium and calcium salts in the form of chlorides and sulphides in water that cannot be eliminated by boiling. We can get rid of the hardness in the water by using washing soda. When washing soda combines with the sulphide and chloride compounds of magnesium and calcium, insoluble carbonates are generated, and hard water is transformed to soft water.

Note :
Hardness of water is hazardous to boilers because it causes salt build up, which affects the boiler's performance. Although hard water is safe to drink, prolonged exposure to it can cause a variety of issues, including: Strains in skin ,Water appliances work harder resulting in higher water bills, Spots appear on clothes and linens.