Q. 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 $a$ account for the shape of gas phase molecules
C) The parameter $a$ accounts for intermolecular interactions present in the molecule
D) The parameter is a correction factor to the volume of the container
Explanation
(c)
In van der Waals’ equation
$\left\lbrack p + \frac{n^{2}a}{V^{2}} \right\rbrack(V - nb) = nRT$
Where, $p =$ pressure,
$V =$ volume,
$T =$ temperature
$n =$ moles of the gas
and parameter ‘$a$’ accounts for intermolecular interactions present in the molecule
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.