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
$\left[p+\frac{n^{2} a}{V^{2}}\right](V-n b)=n R T$
For one mole $(n=1)$
$\left(p+\frac{a}{V^{2}}\right)(V-b)=R T$