A mixture of benzene and toluene is to be distilled in a batch still with one equilibrium stage (total of two equilibrium contacts). The column has a total condenser and reflux is returned as a saturated liquid. The initial feed is 10.0 kmol and is 50 mol% benzene. Distillation is continued at a constant reflux ratio L/D = 1 until the concentration of benzene in the still reaches 20-mole %.
(a) Find Xp,avg. (15 points)
(b) Find Wfinal (kmoles) and Dtotal. (15 points)