If the compressibility factor $Z < 1$ at $STP$,what will be the molar volume?

In a mole of water vapour at $STP$,the volume actually occupied or taken by the molecules (i.e.,Avogadro's No. $\times$ Volume of one molecule) is

What is the Boyle temperature?

For real gases,the relation between $P$,$V$ and $T$ is given by the van der Waals equation,$(P + \frac{an^2}{V^2})(V - nb) = nRT$. For the following gases $CH_4, CO_2, O_2, H_2$,which gas will have $(i)$ highest value of $'a'$ $(ii)$ lowest value of $'b'$?

Write the van der Waals equation.

Gases deviate from ideal gas behavior because the molecules $...$