Any gas shows maximum deviation from ideal gas behavior at

The pressure $(p)$ and volume $(V)$ isotherm of a van der Waals' gas,at the temperature at which it undergoes gas to liquid transition,is correctly represented by

The $P$ vs $V$ graph is plotted for $1$ $mole$ of a hypothetical gas. Based on the given isotherms at $200 \ K$ and $300 \ K$,determine the range of $\frac{a}{b}$ for this gas in $atm-L \ mole^{-1}$. [Given: $R = 0.08 \ atm-L \ mole^{-1} \ K^{-1}$]

The correct equation for one mole of a real gas is ($a, b$ are constants)

The Van der Waals constant '$a$' for the gases $O_2$,$N_2$,$NH_3$ and $CH_4$ are $1.3$,$1.390$,$4.170$ and $2.253 \ L^2 \ atm \ mol^{-2}$ respectively. The gas which can be most easily liquefied is

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 $P$?