A liquid feed of 100 kg mol/h of benzene-toluene at the boiling point contains 55 mol % benzene and 45 mol % toluene. It is being distilled at 101.32 kPa pressure to give a distillate with xD= 0.98 and a bottoms of xW= 0.04. Using a reflux ratio of 1.3 times the minimum and the enthalpy-concentration method, do as follows: a) Determine the theoretical number of trays needed. b) Calculate the condenser and reboiler heat loads. c) Determine the minimum number of theoretical trays at total reflux.