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JEE Main · 2023 · 30 Jan 2023 · Shift 2 · Environmental Chemistry

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The water quality of a pond was analysed and its BOD was found to be 4. The pond has
  1. (A)Highly polluted water
  2. (B)Water has high amount of fluoride compounds
  3. (C)Very clean water✓ Correct
  4. (D)Slightly polluted water

Answer: (C)

Solution

Biochemical oxygen demand measures the oxygen that microorganisms use in breaking down organic matter in water, so a small value signals little biodegradable pollution. Clean water shows a biochemical oxygen demand of only a few parts per million, whereas heavily polluted water runs to seventeen or more. A value of lies below the clean-water mark, so the pond holds very clean water.

JEE Main · 2023 · 30 Jan 2023 · Shift 2 · Single correct option

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