What are the most favourable conditions to liquefy a gas?

At what pressure does $SO_2$ gas liquefy at room temperature?

The critical temperatures for carbon dioxide $(CO_2)$ and methane $(CH_4)$ are $31.1 \, ^\circ C$ and $-81.9 \, ^\circ C$ respectively. Which of the following statements is correct regarding their liquefaction?

What is the value of the critical temperature of water (in $K$)?

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.

According to Andrews isothermals,at what temperature does carbon dioxide gas start to condense at $73 \ atm$ (in $^{\circ} C$)?