Question

The van der Waals' equation for a real gas is given by the formula $\left(P+\frac{n^{2} a}{V^{2}}\right)(V-n b)=n R T$ where $P, V, T$ and $n$ are the pressure, volume, temperature and the number of moles of the gas. Which one is the correct interpretation for the parameter a?

• A. The parameter a accounts for the finite size of the molecule, riot included temperature in the ideal gas law
• B. The parameter a accounts for the shape of gas phase molecules
• C. The parameter a accounts for intermolecular interaction's present in the molecule
• D. The parameter a has no physical significance and van der Waals? introduced it as a numerical correction factor only

Answer 1

Answer: (C)

In van der Waals' equation for real gases, a accounts for intermolecular interactions present in the gases.