Distinguish between vapor and gas.

What is critical temperature $(T_{C})$?

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

Explain the liquefaction of real gases and permanent gases.

Which of the following statements is incorrect?

Which of the following gases has the highest critical temperature?