The inversion temperature $T_i \, (K)$ of hydrogen is (given van der Waal's constants $a$ and $b$ are $0.244 \, atm \, L^2 \, mol^{-2}$ and $0.027 \, L \, mol^{-1}$ respectively).

Which gas among the following is the easiest to liquify?

$A$ gas has a compressibility factor of $0.5$ and a molar volume of $0.4 \ dm^3 \ mol^{-1}$ at a temperature of $800 \ K$ and pressure $x \ atm$. If it shows ideal gas behaviour at the same temperature and pressure,the molar volume will be $y \ dm^3 \ mol^{-1}$. The value of $x / y$ is . . . . . .
[Use: Gas constant,$R = 8 \times 10^{-2} \ L \ atm \ K^{-1} \ mol^{-1}$ ]

The pressure $(p)$ and volume $(V)$ isotherm of a van der Waals' gas,at the temperature at which it undergoes gas to liquid transition,is correctly represented by

Identify the correct variation of pressure $(p)$ and volume $(V)$ of a real gas $(A)$ and an ideal gas $(B)$ at constant temperature. ($y = p$; $x = V$)

When helium is allowed to expand into vacuum,a heating effect is observed. The reason for this is that