The correct statement amongst the following is: 

Options

A. For every gas there exists a characteristic temperature above which it cannot be liquefied no matter however high is the pressure applied called critical temperature of the gas.
B. For every gas there exists a characteristic temperature at which its compressibility factor is equal to unity for some range of pressure.
C. Amongst `He, N_2, O_2 and CO_2,CO_2` has the lowest value of "a" and He has the lowest value "b" where a and bare vander walls constants of the gas.
D. The extent of departure of Z (compressibility factor) from unity is the measure of the extent of deviation from ideal behavior.

Answer

A, B, D

Explanation

a) `T_c " " ` b) `T_b`
c) `CO_2` has highest value of aa
d) Z gives measure of deviation.