Question

Which one, among the following, is the van der Waals' equation, describing the behaviour of one mole of a real gas over wide ranges. temperature and pressure?

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

Answer 1

Answer: (A)

The van der Waals' equation for $n$ moles of a gas is
$\left[p+\frac{n^{2}a}{V^2}\right](V-nb)=nRT$
For one mole $(n=1)$
$\left(p+\frac{a}{V^2}\right)(V-b)=RT$