Question

Identify the wrong relation for real gases

• A. \(z=\frac{V_{ideal}}{V_{real}}\)
• B. \(P_{ideal}=P_{real}+\frac{an^2}{V^2}\)
• C. \(V_{ideal}=V_{real}-nb\)
• D. \((p+\frac{a}{V^2})(V-b)=RT\)

Answer 1

The Correct Option is A, C

The question asks to identify the wrong relation for real gases. Let's evaluate each option:

Explanation of each option:

• (A) \( Z = \frac{V_{\text{ideal}}}{V_{\text{real}}} \): This is incorrect. The correct definition of compressibility factor \( Z \) involves pressure and volume relationships, not just the ratio of ideal and real volumes.
• (B) \( P_{\text{ideal}} = P_{\text{real}} + \frac{a n^2}{V^2} \): This is correct. This equation is part of the Van der Waals equation, where \( a \) is a constant related to intermolecular forces.
• (C) \( V_{\text{real}} = V_{\text{ideal}} - nb \): This is incorrect. The volume occupied by the gas molecules adds to the ideal gas volume, so the correct equation is \( V_{\text{real}} = V_{\text{ideal}} + nb \).
• (D) \( \left( p + \frac{a}{V^2} \right) (V - b) = RT \): This is correct. It is the Van der Waals equation for real gases.

Conclusion:

The incorrect relations are (A) and (C).