Question

A gas at 350 K and 15 bar has molar volume 20 percent smaller than that for an ideal gas under the same conditions. The correct option about the gas and its compressibility factor (Z) is :

(1)   Z > 1 and attractive forces are dominant

(2)  Z > 1 and repulsive forces are dominant

(3)  Z < 1 and attractive forces are dominant

(4)  Z < 1 and repulsive forces are dominant

Answer 1

Correct option  (3) Z < 1 and attractive forces are dominant

Explanation:

•  Compressibility factor(Z) = V_real/V_ideal

∴  V_real/V_ideal; Hence Z < 1

•  If Z < 1, attractive forces are dominant among gaseous molecules and liquefaction of gas will be easy.