The van der Waals equation is valid for $......$.

The variation of the compressibility factor $(Z)$ with pressure $(P$ in $bar)$ for some gases is shown in the figure below. Identify the gases $(A)$, $(B)$, and $(C)$.

Which gas shows real behavior?

In the van der Waals equation,which term indicates the presence of attractive forces in a gas?

Consider the van der Waals constants,$a$ and $b$,for the following gases:

Gas	$Ar$	$Ne$	$Kr$	$Xe$
$a / (atm \ dm^6 \ mol^{-2})$	$1.3$	$0.2$	$5.1$	$4.1$
$b / (10^{-2} \ dm^3 \ mol^{-1})$	$3.2$	$1.7$	$1.0$	$5.0$

Which gas is expected to have the highest critical temperature?

The $Z$ vs $P$ graph for four gases is given below at the same temperature.
Which of the gases will have the highest value of critical temperature $(T_c)$?