When your parents or grandparents were in college, it was not uncommon to “borrow” some “pure” ethanol (grain alcohol) from the university to add to a party punch. However, because of the azeotrope between ethanol and water, “pure” ethanol is not easy to manufacture. At that time, it was not uncommon for benzene to be added as an entrainer to break the azeotrope. Of course, this means that all “pure” ethanol contained trace amounts of benzene, which was later identified as a carcinogen. By plotting both residue curves and TPxy diagrams for the ethanol water system, suggest a method for purifying ethanol by adding benzene as an entrainer. Assume that the UNIQUAC model applies and that the feed stream of ethanol and water is equimolar and at atmospheric pressure.