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

What happens when $CO_2$ is compressed and expanded at a constant temperature of $30.98 \, ^\circ C$?

An ideal gas cannot be liquefied because ........

What are the critical constants?

Explain the liquefaction of $CO_2$ gas using the Thomas Andrews plot,including the effects of temperature and pressure,and define the critical constants.

Gases possess characteristic critical temperature which depends upon the magnitude of intermolecular forces between the particles. Following are the critical temperatures of some gases.

$Gases$	$H_2$	$He$	$O_2$	$N_2$
$Critical \ temperature \ (K)$	$33.2$	$5.3$	$154.3$	$126$

From the above data,what would be the decreasing order of liquefaction of these gases?