Question

Given, Van der waals equation for non-ideal gas
$(P+\frac{a{n}^2}{V^2})(V-nb)=nRT$
The term that correctly describes intermolecular forces of attraction between the molecules is:

• A. $b$
• B. $RT$
• C. $\frac{a{n}^2}{V^2}$
• D. $(RT{)}^{-1}$

Answer 1

The correct option is C $\frac{a{n}^2}{V^2}$

As pressure of a real gas or non-ideal gas is lower (compare to ideal) due to the significant intermolecular forces of attraction between the molecules. So a pressure correction term which is $\frac{a}{V^2}$ added in the equation so,
$P_{\text{correction}}=\left(\frac{a{n}^2}{V^2}\right)$
$a=$ van der Waal constant and depend on nature of gas
and the van der Waal equation is
$(P+\frac{a{n}^2}{V^2})(V-nb)=nRT$