Question

At low pressure, the van der Waals equation is reduced to:

• A. \( Z = \frac{P V_m}{RT} - \frac{a}{V_m} \)
• B. \( Z = \frac{P V_m}{RT} + \frac{b}{RT} P \)
• C. \( Z = P V_m = RT \)
• D. \( Z = \frac{P V_m}{RT} - \frac{a}{V_m} \)

Hint:

At low pressures, the ideal gas law approximates real gases more accurately, and the van der Waals equation simplifies accordingly.

Answer 1

The Correct Option is A

At low pressures, the term \( \frac{b}{RT} P \) becomes negligible and the van der Waals equation simplifies to this expression.
Final Answer: \[ \boxed{Z = \frac{P V_m}{RT} - \frac{a}{V_m}} \]