Question

write four disadvantages of using hard water for cooking purposes ​

Answer 1

Explanation:

1. Hard water is unfit for washing as it is difficult to form lather with soap.
2. Scum may form in a reaction with soap, wasting the soap.
3. Furring of tea kettles will take place due to the formation of carbonates of calcium and magnesium.
4. Hard blocks hot water pipes.

Answer 2

Answer:

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(i) Washing: Hard water, when used for washing purposes, does not lather freely with soap. On the other hand, it produces sticky precipitates of calcium and magnesium soaps. The formation of such insoluble, sticky precipitated continues, till all calcium and magnesium salts present in water are precipitated. After that, the soap (e.g., sodium stearate) gives lather with water. Thus;

This causes wastage of soap being used. Moreover, the sticky precipitate (of calcium and magnesium soaps) adheres on the fabric/cloth giving spots and streaks. Also presence of iron salts may cause staining of cloth.

(ii) Bathing: Hard water does not lather freely with soap solution, but produces sticky scum on the bath-tub and body. Thus, the cleansing quality of soap is depressed and a lot of it is wasted.

(iii) Cooking: Due to the presence of dissolved hardness-producing salts, the boiling point of water is elevated. Consequently, more fuel and time are required for cooking certain foods such as pulses, beans and peas do not cook soft in hard water. Also tea or coffee, prepared in hard water, has an unpleasant taste and muddy-looking extract. Moreover, the dissolved salts are deposited as carbonates on the inner walls of the water heating utensils.

(iv)Drinking: Hard water causes bad effect on our digestive system. Moreover, the possibility of forming calcium oxalate crystals in urinary tracks is increased.