Question

Critical temperature for $C{O}_2$ and methene are ${31.1}^0$ C and $-{81.9}^0$ C respectively. Which of these has stronger intermolecular forces and why?

Answer 1

Critical temperature $T_c=\frac{8a}{27Rb}$

As, we know that higher the value of ${}^{\prime }{a}^{\prime }$ stronger the intermolecuar

forces.

In the above formula

$T_c\propto a$, $T_c\propto \frac{1}{b}$

Therefore higher value of critical temperature gives greater value of ${}^{\prime }{a}^{\prime }$, i.e

stronger intermolecualr forces of attraction.

$\therefore C{O}_2$ has stronger intermolecular forces of attraction.