Which of the following is correct?

Options

A. A real gas approaches ideal gas behaviour at low pressure and high temperature
B. Liquification of a real gas is possible at low temperature and high pressure
C. Both of them
D. None of them

Answer

To solve the question regarding the behavior of real gases and the conditions for liquefaction, we can break it down into a step-by-step analysis of the statements provided.

### Step-by-Step Solution:

**Step 1: Analyze Option 1**
- The first statement claims that a real gas approaches ideal gas behavior at low pressure and high temperature.
- **Explanation**: In ideal gas behavior, we assume there are no intermolecular forces and that the volume of the gas molecules is negligible compared to the volume of the container.
- When pressure is lowered, gas molecules spread out, reducing the effect of intermolecular forces. Increasing temperature increases the kinetic energy of the molecules, causing them to move more freely.
- **Conclusion**: Therefore, at low pressure and high temperature, real gases behave more like ideal gases. This statement is correct.

**Step 2: Analyze Option 2**
- The second statement suggests that liquefaction of a real gas is possible at low temperature and high pressure.
- **Explanation**: Liquefaction occurs when gas molecules are forced close together, which can happen by increasing pressure or lowering temperature. At low temperatures, the kinetic energy of the molecules decreases, allowing intermolecular forces to take effect and pull the molecules closer together.
- High pressure also compresses the gas, facilitating liquefaction.
- **Conclusion**: Thus, the conditions of low temperature and high pressure are indeed sufficient for the liquefaction of a real gas. This statement is also correct.

**Step 3: Final Conclusion**
- Since both statements (Option 1 and Option 2) are correct, the correct answer to the question is that both options are valid. Therefore, the answer is Option 3, which states that both statements are correct.

### Final Answer:
The correct answer is Option 3: Both statements are correct.