Consider the following figure. Which of the following gases show negative as well as positive deviation from the ideal gas behaviour?

In the van der Waals equation for gases,what does the constant $b$ represent?

Van der Waals equation of state is obeyed by real gases. For $n$ moles of a real gas,the expression will be

Which among the following statements is/are incorrect regarding real gases?
$(i)$ Their compressibility factor is never equal to unity $(Z \neq 1)$.
$(ii)$ The deviations from ideal behavior are less at low pressures and high temperatures.
$(iii)$ Intermolecular forces among gas molecules are equal to zero.
$(iv)$ They obey Van der Waals equation,$PV = nRT$.

What is the reason for the deviation of pressure from ideal behavior?

Consider the following table:

Gas	$a / (kPa \cdot dm^6 \cdot mol^{-2})$	$b / (dm^3 \cdot mol^{-1})$
$A$	$642.32$	$0.05196$
$B$	$155.21$	$0.04136$
$C$	$431.91$	$0.05196$
$D$	$155.21$	$0.4382$

$a$ and $b$ are van der Waals constants. The correct statement about the gases is: