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Q124 (IAS/2000) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Applied everyday chemistry Answer Verified

Consider the following statements : Hard water is not suitable for I. drinking. II. washing cloths with soap. III. use in boilers. IV. irrigating crops. Which of these statements are correct ?

Result
Your answer: —  Â·  Correct: D

Explanation

Hard water is generally considered unsuitable for the following purposes:

  • Drinking: Extremely hard water can have an unpleasant taste, disrupt the body's ionic balance, and cause minor digestive issues.
  • Washing clothes with soap: The calcium and magnesium ions in hard water react with ordinary soap to form an insoluble white precipitate called scum. This prevents lathering and leads to wastage of soap.
  • Use in boilers: When hard water is heated, dissolved salts precipitate and deposit as hard scales on the inner walls of the boiler. This reduces heat efficiency, wastes energy, and can lead to boiler explosions.
  • Irrigating crops: Repeated irrigation with hard water leads to the accumulation of excess calcium and magnesium salts in the soil, which increases soil alkalinity and adversely affects plant growth over time.

Therefore, all four statements are correct.

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