question_answer

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 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