$A, B, C$ and $D$ are four different gases with critical temperatures $304.1, 154.3, 405.5$ and $126.0 \ K$ respectively. While cooling the gas,which gets liquefied first?

Gases possess characteristic critical temperature which depends upon the magnitude of intermolecular forces between the gas particles. Critical temperatures of ammonia and carbon dioxide are $405.5 \ K$ and $304.10 \ K$ respectively. Which of these gases will liquefy first when you start cooling from $500 \ K$ to their critical temperature?

The temperature and pressure at which ice,liquid water,and water vapour can exist together are:

The critical temperatures $(T_C)$ of some gases are given below:

Gases	$H_2, He, O_2$
$T_C \ (K)$	$33.2, 5.3, 154.3$

Based on the above data,what is the order of liquefaction of these gases? Start writing the order from the gas that liquefies first.

Explain the liquefaction of real gases and permanent gases.

Ice,water,and steam coexist in equilibrium at which of the following conditions?