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

The liquified gas that is used in dry cleaning along with a suitable detergent is

Why does the boundary between the liquid phase and the gaseous phase disappear upon heating a liquid up to the critical temperature in a closed vessel? In this situation,what will be the state of the substance?

Under what conditions can an ideal gas,which follows the kinetic gas equation,be liquefied?

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.

The number of statements,which are correct with respect to the compression of carbon dioxide from point $(a)$ in the Andrews isotherm from the following is $..........$.
$A.$ Carbon dioxide remains as a gas up to point $(b)$
$B.$ Liquid carbon dioxide appears at point $(c)$
$C.$ Liquid and gaseous carbon dioxide coexist between points $(b)$ and $(c)$
$D.$ As the volume decreases from $(b)$ to $(c)$,the amount of liquid decreases