Question

Which from following gases causes the depletion of ozone layer in upper atmosphere?

• A. NO
• B. NO$_2$
• C. N$_2$O
• D. N$_2$O$_5$

Hint:

CFCs and Nitrogen oxides (NO) are the two major classes of ozone-depleting substances.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question asks for the nitrogen oxide gas that significantly contributes to ozone layer depletion in the stratosphere.
Step 2: Detailed Explanation:
1. Nitric oxide (NO) is released into the stratosphere by supersonic jets and through natural processes.
2. NO reacts rapidly with ozone ($O_3$) to form nitrogen dioxide and oxygen:
\[ NO(g) + O_3(g) \rightarrow NO_2(g) + O_2(g) \] 3. This catalytic cycle continuously destroys ozone molecules.
Step 4: Final Answer:
NO is the primary gas among the options that causes ozone depletion.