Question

State the disadvantage of using hard water.

Answer 1

Hint: We have known for a long time that hard water does not form lather when it is combined with soap. It is considered as a kind of impurity. This is caused due to the movement of water through soil, rocks etc. which makes some minerals to dissolve in water.

Complete step by step answer:
We know that calcium and magnesium cause hardness in water. When the amount of these minerals is increased, the hardness of water is also increased.
There are several disadvantages of hard water in two stages:
Domestic use:
Some sticky precipitates of calcium and magnesium soaps are produced in hard water. When all the salts of calcium and magnesium are precipitated, the sticky precipitate is not formed and soap gives lather with water. The chemical reaction is given below:
${{{C}}_{17}}{{{H}}_{35}}{{COONa + }}{{{H}}_2}{{O}} \to {{{C}}_{17}}{{{H}}_{35}}{{COOH + NaOH}}$
Soap
${{{C}}_{17}}{{{H}}_{35}}{{COOH}} + {{{C}}_{17}}{{{H}}_{35}}{{COONa}} \to $ lather
Stearic acid
When this sticky precipitate is stuck on clothes, it produces spots on them. Staining of cloth is produced due to the presence of salts.
During bathing, when we use soap, it produces scum on the body or bathroom. This will decrease the cleansing property of soaps.
During boiling of water, its boiling point is increased when we use hard water. Thereby more time and fuel is needed for cooking.
When we consider the effects of this type of water to the body, it has a very bad effect on our digestive system. It also forms crystals of calcium oxalate in urinary tracts.
Industrial uses:
It has several bad effects of hard water in textile industry, sugar industry, dyeing industry, paper industry, laundry, concrete making, pharmaceutical industry etc.

Note: When the water, having sulfates, nitrates, carbonates, etc. is used in refining of sugar, it is difficult for the sugar to crystallize. The produced sugar has the tendency to become liquid. Sometimes, water which has chlorides and sulfates is used for preparation of concrete.