When does the graph of $p \propto \frac{1}{V}$ not result in a straight line?

Compressibility factor,$Z$,of a gas is given as $Z = \frac{pV}{nRT}$.
$(i)$ What is the value of $Z$ for an ideal gas?
$(ii)$ For a real gas,what will be the effect on the value of $Z$ above Boyle's temperature?

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 $Z$.

Under which conditions does a real gas show maximum deviation from ideal gas behavior?

In the van der Waals equation,which term indicates the presence of attractive forces in a gas?

Statement $-1$: The compressibility factor at the critical point is the same for different gases following van der Waal's equation.
Statement $-2$: The compressibility factor is independent of pressure at the critical temperature.