The boiling point of ethanol (at 1 atm) = 78 C, its latent heat of vaporization Lv = 8.54 x 105 J/kg, the density of the liquid = 790 kg/m3 , and its molecular weight = 0.046 kg/mole. 1 mol of liquid ethanol boils at 78 C and becomes vapor at 1 atm. Assume that the vapor is an ideal gas (not a good approximation). a) How much work is done on the ethanol? b) What is the change in internal energy of the ethanol?