Maximum deviation from ideal gas behavior is expected from which of the following gases?

In the van der Waals equation of state for a real gas,the term representing intermolecular forces is .......

In van der Waals equation of state,the constant $b$ is a measure of

What is compressibility factor $(Z)$? Explain $(i)$ deviation factor $(Z = 1)$,$(ii)$ $Z > 1$,$(iii)$ $Z < 1$,$(iv)$ deviation graph,and $(v)$ the relation between molar volume and $Z$.

The relation between pressure exerted by an ideal gas $(P_{ideal})$ and observed pressure $(P_{real})$ is given by the equation
$P_{ideal} = P_{real} + \frac{an^2}{V^2}$
$(i)$ If pressure is taken in $N \ m^{-2}$,number of moles in $mol$,and volume in $m^3$,calculate the unit of $a$.
$(ii)$ What will be the unit of $a$ when pressure is in atmosphere and volume in $dm^3$?

For $NH_3$ gas,the $Z$ vs pressure $(P)$ curve at different temperatures is shown. What is the correct order of temperatures? (Given $T_B$ = Boyle temperature)