Hard water is not suitable for

1. Drinking
2. Washing cloth with soap
3. Use in boilers
4. Irrigating crops

Select the correct answer using the codes given below:
a) 1 and 3 only
b) 2 and 3 only
c) 1, 2 and 4 only
d) 1, 2, 3 and 4

Ans-[D]

Explanation- Hard water is that water which contains salts of calcium and magnesium principally as bicarbonates, chlorides, and sulfates. Ferrous iron may also be present in this water. This hardness is of two types, temporary and permanent.

Hardness that is caused by calcium bicarbonate is known as temporary, because boiling converts the bicarbonate to the insoluble carbonate; hardness from the other salts is called permanent.

This hard water is unfit for drinking as salt presents reacts with acids in stomach and cause digestive disorders.

These salts of hard water forms an insoluble gelatinous curd on reaction with soap and lather formation doesn’t occur and as such they are not fit for washing clothes even.

This water is unsuitable for boilers as calcium and magnesium in hard waters form a hard, adherent scale on the plates. As a result fuel consumption is increased, and the boiler deteriorates rapidly through increased external overheating.

Hard water is unsuitable for crops as salts present disturbs the normal chemistry of soil and clogs the irrigation channel pathways of plants.