JEE Main · 2022 · 25 Jun 2022 · Shift 2 · Environmental Chemistry

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Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R

Assertion A: Polluted water may have a value of BOD of the order of 17 ppm.

Reason R: BOD is a measure of oxygen required to oxidise both the biodegradable and non-biodegradable organic material in water.

In the light of the above statements, choose the most appropriate answer from the options given below.
  1. (A)Both A and R are correct and R is the correct explanation of A.
  2. (B)Both A and R are correct but R is NOT the correct explanation of A.
  3. (C)A is correct but R is not correct.✓ Correct
  4. (D)A is not correct but R is correct.

Answer: (C)

Solution

Clean water has BOD less than 5 ppm, while highly polluted water has BOD ≥ 17 ppm, so Assertion A is correct. However, BOD (Biochemical Oxygen Demand) measures only the oxygen required to oxidize biodegradable organic matter, not non-biodegradable material. Therefore, Reason R is incorrect.

JEE Main · 2022 · 25 Jun 2022 · Shift 2 · Single correct option

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