JEE Main · 2019 · 08 Apr 2019 · Shift 1 · Environmental Chemistry

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Assertion : Ozone is destroyed by CFCs in the upper stratosphere.

Reason : Ozone holes increase the amount of UV radiation reaching the earth.
  1. (A)Assertion and reason are incorrect
  2. (B)Assertion is false, but the reason is correct
  3. (C)Assertion and reasons are both correct, and the reason is the correct explanation for the assertion.
  4. (D)Assertion and reason are correct, but the reason is not the explanation for the assertion.✓ Correct

Answer: (D)

Solution

The assertion is sound: chlorofluorocarbons release chlorine radicals in the stratosphere that catalytically destroy ozone. The reason is also true, since a depleted ozone layer does let more ultraviolet radiation reach the ground. But the reason states a consequence of ozone loss, not the mechanism by which CFCs cause it, so it does not explain the assertion. Both statements are correct while the reason is not the explanation of the assertion.

JEE Main · 2019 · 08 Apr 2019 · Shift 1 · Single correct option

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