Question

Ozone concentration in the atmosphere is reduced by

• A. CO2 and O2
• B. H2S and CH4
• C. CFC and Cl2
• D. N2 and N2O

Hint:

Ozone depleting substances:
- CFCs (chlorofluorocarbons).
- Halons.
- Carbon tetrachloride.
- Methyl chloroform.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
This question tests knowledge of ozone depletion and the chemicals responsible.

Step 2: Detailed Explanation:
Ozone depletion is primarily caused by chlorofluorocarbons (CFCs) and chlorine (Cl2).
CFCs release chlorine atoms in the stratosphere, which catalyze ozone destruction.
CO2 and O2 (A): Not ozone-depleting substances.
H2S and CH4 (B): Not major ozone depleters.
N2 and N2O (D): N2O is a greenhouse gas but not a major ozone depleter.
Thus, CFCs and Cl2 reduce ozone concentration.

Step 3: Final Answer:
Thus, ozone concentration is reduced by CFC and Cl2, which corresponds to option (C).
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