Gases can be liquefied by:

What is the relationship between the liquefaction of gases,compression,and temperature?

Critical temperature for carbon dioxide and methane are $31.1^{\circ} C$ and $-81.9^{\circ} C$ respectively. Which of these has stronger intermolecular forces and why?

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

Isotherms of carbon dioxide at various temperatures are represented in the figure. Answer the following questions based on this figure.
$(i)$ In which state will $CO_2$ exist between the points $a$ and $b$ at temperature $T_1$?
$(ii)$ At what point will $CO_2$ start liquefying when temperature is $T_1$?
$(iii)$ At what point will $CO_2$ be completely liquefied when temperature is $T_2$?
$(iv)$ Will condensation take place when the temperature is $T_3$?
$(v)$ What portion of the isotherm at $T_1$ represents liquid and gaseous $CO_2$ at equilibrium?

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