Question

Which of the following is responsible for depletion of the ozone layer in the upper strata of the atmosphere

• A. Ferrocene
• B. Fullerenes
• C. Freons
• D. Polyhalogens

Answer 1

The Correct Option is C

The question asks which substance is responsible for the depletion of the ozone layer in the upper atmosphere. Let us analyze the options provided:

1. Ferrocene: This is an organometallic compound but is not known for affecting the ozone layer.
2. Fullerenes: These are molecules made entirely of carbon, but they do not play a role in ozone depletion.
3. Freons: These are chlorofluorocarbons (CFCs), widely recognized for their destructive impact on the ozone layer. They were commonly used in refrigeration, air conditioning, and as propellants in aerosol applications. When released into the atmosphere, freons rise and eventually reach the stratosphere. Here, they are broken down by UV radiation, releasing chlorine atoms, which catalyze the breakdown of ozone (O₃) into oxygen (O₂), thus depleting the ozone layer.
4. Polyhalogens: These compounds contain more than one halogen atom, but on their own, are not directly indicated to cause ozone depletion.

Correct Answer: Freons are responsible for the depletion of the ozone layer in the upper strata of the atmosphere due to the release of chlorine atoms during their breakdown.

Conclusion: From the analysis above, it is clear that freons, also known as chlorofluorocarbons (CFCs), are the substances specifically responsible for causing significant harm to the ozone layer. The interaction of freons with ozone results in a chemical reaction that reduces the concentration of ozone in the stratosphere.