To analyze the assertion and reason provided in the question, we will break down the concepts of ozone depletion, the role of chlorofluorocarbons (CFCs), and the mechanism by which they contribute to ozone depletion.
### Step-by-Step Solution:
1. **Understanding the Assertion (A)**:
- The assertion states that "Ozone depletion potential is maximum in CFCs."
- This means that among various substances, CFCs have the highest capability to deplete the ozone layer.
2. **Understanding the Reason (R)**:
- The reason states that "CFC loses active chlorine."
- This suggests that when CFCs are broken down in the atmosphere, they release chlorine atoms, which are active agents in the depletion of ozone.
3. **Mechanism of Ozone Depletion**:
- CFCs are chlorofluorocarbons, which are compounds made of carbon, chlorine, and fluorine.
- When CFCs are released into the atmosphere, they eventually reach the stratosphere, where they are broken down by ultraviolet (UV) radiation from the sun.
- The breakdown of CFCs releases chlorine atoms. For instance, when a CFC molecule is exposed to UV light, it can lose a chlorine atom, forming chlorine radicals (Cl•).
- These chlorine radicals are highly reactive and can interact with ozone (O₃) molecules.
4. **Interaction with Ozone**:
- The chlorine radical reacts with ozone, leading to the following reaction:
\[
\text{Cl•} + \text{O}_3 \rightarrow \text{ClO} + \text{O}_2
\]
- In this reaction, a chlorine atom combines with an ozone molecule, forming chlorine monoxide (ClO) and releasing molecular oxygen (O₂).
- The chlorine monoxide can further react with a free oxygen atom:
\[
\text{ClO} + \text{O} \rightarrow \text{Cl•} + \text{O}_2
\]
- This regeneration of the chlorine radical means that one chlorine atom can destroy many ozone molecules before it is removed from the atmosphere.
5. **Conclusion**:
- Therefore, the assertion that CFCs have the maximum ozone depletion potential is correct, and the reason that CFCs release active chlorine, which contributes to this depletion, is also correct.
### Final Answer:
Both the assertion (A) and the reason (R) are true, and the reason correctly explains the assertion.
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