2) A liquid with a molar composition of 60% benzene and 40% toluene at 20C is evaporated in a partial evaporator at a constant temperature of 50C under vacuum. The vapor and liquid streams leaving the evaporator are in equilibrium and the molar composition of benzene in the vapor stream is 68.4% and the molar composition of the benzene in the liquid stream is 40%. Calculate the heat (kJ/kmol) that must be supplied to the evaporator per kilomole of the feed. Cp Benzene (l)=62.55+23.4102T, T: Kelvin Cp Toluene (l)=165kJ/kmolK Cp Benzene (v)=74.06+32.95102T25.2105T2,T : Celcius Cp Toluene (v)=94.18+38102T27.86105T2,T : Celcius