For which of the following gases is the value of the van der Waals constant $'a'$ expected to be the highest?

The temperature at which the second virial coefficient of a real gas is zero is called:

When does a gas deviate the most from its ideal behaviour?

For one mole of a van der Waals gas when $b=0$ and $T=300 \ K$,the $PV$ vs. $1/V$ plot is shown below. The value of the van der Waals constant $a$ (in $\text{atm} \cdot \text{liter}^2 \cdot \text{mol}^{-2}$) is:

For a real gas,deviations from ideal gas behavior are maximum at:

The compressibility factor $(Z)$ of a gas is greater than unity at $1 \, atm$ and $273 \, K$. Therefore: