Question

Which of the following statements on critical constants of gases are correct?

I : Larger the $\frac{T_c}{P_c}$ value of a gas, larger would be the excluded volume.

II : Critical temperature ($T_c$) of a gas is greater than its Boyle's temperature ($T_B$).

III : At the critical point in the Van der Walls gas isotherm.

$⟮\frac{dP}{d{V}_m}⟯T_c=0$

• A. I and II
• B. I and III
• C. II and III
• D. I, II and III

Answer 1

The correct option is D

I, II and III

While I and II are obvious from formulas for $T_c$ and $P_c$ and $T_B$ .

III is true by defnition . Although it is beyond the scope, please make a note of this property.