The term that corrects for the attractive forces present in a real gas in the van der Waals equation is

Which of the following statements is false based on the provided graph of compressibility factor $Z$ versus pressure $P$?

Four gases $P, Q, R$ and $S$ have almost same values of $b$ but their $a$ values ($a, b$ are van der Waals' constants) are in the order $Q < R < S < P$. At a particular temperature among the four gases, the most liquefiable one is

Pressure exerted by $1 \, mole$ of methane in a $0.25 \, L$ container at $300 \, K$ using van der Waals equation is ............... $atm$ (given $a = 2.253 \, atm \, L^2 \, mol^{-2}, b = 0.0428 \, L \, mol^{-1}$):

Dominance of strong repulsive forces among the molecules of the gas ($Z =$ compressibility factor)

Explain real gases showing deviations from ideal gas with correction of pressure and volume and derive van der Waals equation.