Question

At low pressure and high temperature, the Vander Waal’s equation is finally reduced (simplified) to :

• A. $PV_{m} = RT$
• B. $\left(P + \frac{a}{V_{m}^{2}}\right) \left(V_{m} - b \right) = RT $
• C. $P(V_{m} - b) RT$
• D. $\left(P + \frac{a}{V_{m}^{2}}\right)V_{m} = RT $

Answer 1

Answer: (A)

At low pressure and high temperature, van der Waal's equation is modified as :

$p V_{m}=R T$ (for 1 mole )

$\because$ At low pressure and high temperature, the terms

$\frac{a}{V^{2}}$ and $b$ becomes very small as compared to $p$ and $V$.