The compressibility factor of a gas is less than $1$ at $STP$. Its molar volume $V_m$ will be

The term that accounts for intermolecular force in Van der Waals equation for non-ideal gas is

The given graph represents the variation of $Z$ (compressibility factor = $\frac{PV}{nRT}$) versus $P$,for three real gases $A, B$ and $C$. Identify the only incorrect statement.

What is the unit of the Van der Waals constant $a$?

Calculate the compressibility factor $(Z)$ of $1 \text{ mole}$ of a certain real gas if it occupies $0.4 \text{ dm}^3$ at $300 \text{ K}$ and $40 \text{ atm}$. [Given: $R = 0.082 \text{ dm}^3 \text{ atm K}^{-1} \text{ mol}^{-1}$]

The compressibility factor $(Z)$ of a gas at moderate pressure is: