JEE Main · 2020 · 05 Sep 2020 · Shift 1 · Environmental Chemistry

The condition that indicates a polluted environment is:

(A) $0.03%$ of $CO X_{2}$ in the atmosphere
(B)pH of rain water to be 5.6
(C)eutrophication✓ Correct
(D)BOD value of 5 ppm

Answer: (C)

Solution

Eutrophication, the over-enrichment of water with nutrients that triggers algal blooms and then strips the water of oxygen, is a clear sign of pollution. The other figures describe healthy conditions:

0.03%

CO X_{2}

is the normal atmospheric level, rain water of pH

5.6

is naturally mildly acidic from dissolved

CO X_{2}

, and a BOD of

5

ppm is characteristic of clean water. The condition pointing to a polluted environment is eutrophication.

JEE Main · 2020 · 05 Sep 2020 · Shift 1 · Single correct option

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