Question

Which of the following represents van der Waals gas below the critical temperature?

• A.
• B.
• C.
• D.

Answer 1

The correct option is C

Van der Waal's equation is
$(P+\frac{a}{V^2})(V-b)=RT$ (for one mole of the gas)

Below the $T_c$ (critical temperature) for certain value of pressure van der Waals equation gives three roots of volume as equation is cubic function of $V$.
Hence, the correct answer is option (c).