Question

Temporary hardness of water can be removed by:
(A) Boiling
(B) Saponification
(C) Clark’s method
(D) Chlorination

Answer 1

Hint :We know that Temporary hardness of water is caused by the presence of dissolved bicarbonate minerals like calcium bicarbonate and magnesium bicarbonate. Try to think of any reaction that could occur in between the metal bicarbonates and calcium hydroxide, and how could the product formed be beneficial in removal of hardness of water.
Water is the main compound that is required for the endurance of life on earth. Water is available in the seas, streams, lakes, ice sheets, and so rain Water is viewed as pure water since it doesn't contain any salt broke down in it however there are disintegrated gases present. Water can be categorized into hard water and delicate water.

Complete Step By Step Answer:
Hard water is formed when water percolates through deposits of limestone, chalk or gypsum which are largely made up of calcium and magnesium bicarbonates and sulphates. Although it has high mineral content, it does not form lather with soap, hence it is not suitable for laundry purposes. The hardness of water is because of the presence of dissolvable bicarbonates, chlorides, and sulfates of calcium and magnesium. Water that doesn't give foam with a cleanser is hard water.
Soft water: It foams with a cleanser. Water which is gotten from the rains is soft water. This water is appropriate for household purposes for instance clothing and cleaning.
Hard water: It is known as hard water due to the presence of salts of calcium and magnesium. Hard water doesn't foam with a cleanser yet rather frames a precipitate.
The presence of magnesium and calcium carbonates in water makes it incidentally hard. For this situation, the hardness in water can be taken out by heating up the water. And this is called temporary hardness of water.
At the point when we heat up water the dissolvable salts of $ Mg{{(HC{{O}_{3}})}_{2}} $ is changed over to $ Mg{{(OH)}_{2}} $ which is insoluble and thus gets precipitated and is eliminated. After filtration, the water we get is soft water.

Note :
First of all you must be very clear with the definition of hard water, as many students make mistakes in that. Also you must be careful with the constituents present in temporary and permanent hard water as it is the key factor guiding the reaction with calcium hydroxide.