Thank you for reporting, we will resolve it shortly
Q.
The critical temperature and critical density of $CO _{2}$ are $27^{\circ} C$ and $0.45 \,g \,cm ^{-3}$ respectively. The van der Waal's constant ' $a$ ' is :-
States of Matter
Solution:
$ d_{C}-\frac{M M}{V_{c}} $
$\Rightarrow 0.45 \,g / cm ^{3}=\frac{44 \,g / mol }{3 b } $
$\Rightarrow b =\frac{44 \,g / mol }{0.45 \times 1000 \,g / L \times 3} $
$\Rightarrow b =\frac{44\, L / mol }{450 \times 3}$
$ \therefore $ from $T _{ C }=\frac{8 a }{27 Rb } $
$ a= \frac{T_{C} \times 27 R b}{8} $
$= \frac{ 300\, K \times 27 \times 0.0821 \,L atm\,k ^{-1} mol ^{-1} \times \frac{44}{450 \times 3}\, L mol ^{-1}}{8} $
$ 2.71 \,L ^{2} atm \,mol ^{-2} $