Question

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

• A. $(P+\frac{a}{V^2})V=RT$
• B. $PV=RT$
• C. $P(V-b)=RT$
• D. $(P+\frac{a}{V^2})(V-b)=RT$

Answer 1

The correct option is B $PV=RT$

According to van der Waals equation $(P+\frac{a}{V^2})(V-b)=RT$ for one mole of the gas.
At high temperature and low pressure, $V$ is large in comparison to ${}^{\prime }{b}^{\prime }$ and $\left(\frac{a}{V^2}\right)$ is negligible in comparison to $P$.
Hence, the equation reduces to $PV=RT$