Question

Depletion of ozone layer is caused by which of the following?

• A. Oxygen
• B. Vapour
• C. Sulphur dioxide
• D. Chlorofluorocarbon

Hint:

CFCs are the major contributors to ozone layer depletion. Use of eco-friendly refrigerants helps reduce ozone damage.

Answer 1

The Correct Option is D

Step 1: Understanding the ozone layer.
The ozone layer is present in the stratosphere and protects life on Earth by absorbing most of the Sun’s harmful ultraviolet (UV) radiation.
Step 2: Identifying the cause of ozone depletion.
The primary agents responsible for ozone depletion are chlorofluorocarbons (CFCs), which are used in air conditioners, refrigerators, and aerosol sprays. When released into the atmosphere, CFCs rise up and break down under UV radiation, releasing chlorine atoms. These chlorine atoms react with ozone molecules, breaking them apart.
\[ \text{Cl} + \text{O}_3 \rightarrow \text{ClO} + \text{O}_2 \] \[ \text{ClO} + \text{O} \rightarrow \text{Cl} + \text{O}_2 \] Each chlorine atom can destroy thousands of ozone molecules.
Step 3: Conclusion.
Hence, the depletion of the ozone layer is caused by chlorofluorocarbons (CFCs).