Question

The van der Waals equation for a real gas is given by the formula $\left(P+\frac{n^{2}a}{V^2}\right)$ $(V-nb)=$ $nRT,$ 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, not 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 interactions present in the molecule
• D. The parameter a has no physical significance and van der Waals introduced it as a numerical correction factor only
• E. The parameter is a correction factor to the volume of the container

Answer 1

Answer: (C)

In van der Waals equation $\left[P+\frac{n^{2}a}{V^2}\right](V-nb)=nRT$ Where, P = pressure, V = volume T = temperature, n = moles of the gas and parameter d accounts for intermolecular inter-actions present in the molecule.