Which statement is correct regarding the equation $Z = PV/RT$?

In the following compressibility factor $(Z)$ versus pressure graph at $300 \, K$,the compressibility of $CH_{4}$ at pressure $< 200 \, bar$ deviates from ideal behaviour because

One of the assumptions of the kinetic theory of gases is that there is no force of attraction between the molecules of a gas. State and explain the evidence that shows that this assumption is not applicable for real gases.

At a given temperature $T$,gases $Ne$,$Ar$,$Xe$,and $Kr$ are found to deviate from ideal gas behaviour. Their equation of state is given as $P = \frac{RT}{V - b}$ at $T$. Here,$b$ is the van der Waals constant. Which gas will exhibit a steeper increase in the plot of $Z$ (compression factor) versus $P$?

Derive the van der Waals equation.

$A$ $Van \ der \ Waals$ real gas acts as an ideal gas under which of the following conditions?