For a real gas, Z shows -

Options

A. `Z lt 1`, gas is less compressible
B. `Z gt 1 ,` gas is more compressible
C. `Z = oo`, for an ideal gas
D. `PV ne nRT`, for real gas

Answer

To solve the question regarding the compressibility factor (Z) for a real gas, we can follow these steps:

### Step 1: Understand the Compressibility Factor (Z)
The compressibility factor (Z) is defined as the ratio of the observed molar volume (V_real) of a gas to the ideal molar volume (V_ideal) of the gas at the same temperature and pressure:
\[ Z = \frac{V_{real}}{V_{ideal}} \]

### Step 2: Analyze the Value of Z for Real Gases
For ideal gases, Z is equal to 1, which means that the observed volume is equal to the ideal volume. However, for real gases, Z can be either less than 1 or greater than 1:
- If \( Z < 1 \): This indicates that the volume occupied by the real gas is less than that predicted by the ideal gas law. This occurs when attractive forces between gas molecules dominate, leading to a smaller volume.
- If \( Z > 1 \): This indicates that the volume occupied by the real gas is greater than that predicted by the ideal gas law. This occurs when repulsive forces between gas molecules dominate, leading to a larger volume.

### Step 3: Conclusion on Compressibility
From the analysis:
- When \( Z < 1 \), the real gas is more compressible than the ideal gas because it occupies less volume.
- When \( Z > 1 \), the real gas is less compressible than the ideal gas because it occupies more volume.

### Final Answer
For a real gas, the compressibility factor \( Z \) can show values either less than 1 (indicating more compressibility) or greater than 1 (indicating less compressibility).

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