The liquefaction behaviour of temporary gases like `CO_(2)` approaches that of `N_(2).O_(2)` (perma-nent gases) as we go -

Options

A. Below absolute zero
B. Above absolute zero
C. Above critical temperature
D. Below critical temperature

Answer

To solve the question regarding the liquefaction behavior of temporary gases like CO₂ as it approaches that of permanent gases like N₂ and O₂, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Liquefaction**:
- Liquefaction refers to the process of converting a gas into a liquid. This occurs when the intermolecular forces between gas molecules are strengthened enough to hold them together in a liquid state.

**Hint**: Remember that liquefaction involves increasing the attractive forces between gas molecules.

2. **Identify Temporary and Permanent Gases**:
- Temporary gases (like CO₂) have stronger intermolecular forces compared to permanent gases (like N₂ and O₂). This means that temporary gases can be liquefied more easily under certain conditions.

**Hint**: Temporary gases have higher critical temperatures due to their stronger intermolecular forces.

3. **Understand Critical Temperature (TC)**:
- The critical temperature is the temperature above which a gas cannot be liquefied, regardless of the pressure applied. For temporary gases, the critical temperature is relatively high compared to permanent gases.

**Hint**: Critical temperature is key in determining the liquefaction behavior of gases.

4. **Analyze the Behavior Above Critical Temperature**:
- Above the critical temperature, the intermolecular forces in temporary gases become weak, and they behave more like permanent gases. This means that their ability to liquefy diminishes, and they act similarly to permanent gases.

**Hint**: Focus on how the behavior of gases changes with temperature, especially in relation to their critical temperature.

5. **Conclusion**:
- Therefore, the liquefaction behavior of temporary gases like CO₂ approaches that of permanent gases like N₂ and O₂ as we go above the critical temperature.

**Final Answer**: The liquefaction behavior of temporary gases like CO₂ approaches that of permanent gases as we go **above critical temperature**.