O Question 3: (a) Develop an expression to determine the fugacity coefficient for a van der Waal's gas with a =3.789Pa(m3/mol)2 and b=2.37104m3/mol. At a temperature of 427.85K and pressure 0.215MPa calculate the following: i. Fugacity coefficient of the gas. ii. Fugacity of the gas. iii. Residual molar free energy of the gas