Question

Does boiling water reduce hardness?

Answer 1

Hint: Hardness of water indicates the presence of a high concentration of minerals in the water. The most commonly dissolved minerals in water are the compounds of calcium, bicarbonate, sodium and magnesium. Due to the boiling of water, these minerals get precipitated.

Complete answer:
Strong water, also called hard water, is rich in dissolved minerals of mainly calcium and magnesium. Hardness of water indicates the presence of a high concentration of minerals in the water.
Boiling water can only remove hardness from water temporarily. It can remove the presence of calcium and bicarbonate ions from water. Permanent hardness of water can be removed by the removal of sodium and magnesium ions which cannot be completely removed by simply boiling the water. Boiling of water removes magnesium ions to some extent but not completely. When the water is boiled, the precipitate is formed of calcium and bicarbonate ions and gets separated out from the pure water. This implies that boiling water can make the water soft to some extent.
Therefore, we can say that boiling of water allows the calcium carbonate and magnesium carbonate to precipitate out. It gets separated out from the pure water, thereby removing the hardness of water.
Hence, boiling of water reduces the harness of the water temporarily.

Note:
In simple words, we can say that the boiling of water undergoes a precipitation reaction where calcium carbonate and magnesium carbonate are precipitates out that result in decrease of hardness of the water. Sometimes, washing soda is also used to get rid of the dissolved calcium and magnesium in hard water.