(a) Using the truncated virial equation of state and the second virial coefficient (which is negative when there are attractive forces), show that the fugacity coefficient is less than one when attractive forces are dominant. (b) Use the truncated virial equation of state and the Pitzer correlation to calculate the fugacity of ethane vapor at T=270K and P=40 bar. (c) Use the Pitzer correlation and the mixing rules to calculate the fugacity of ethane in an ethane (1) / ethylene oxide (2) vapor mixture at T=270K,P=40 bar, and y1=0.25. (It is known that f^2 is 17.89 bar and that B22=139cm3/mol.)