Enriching Tower for Benzene-Toluene. An enriching tower is fed 100 kg mol/h of a saturated vapor feed containing 40 mol % benzene (A) and 60 mol % toluene (B) at 101.32 kPa abs. The distillate is to contain 90 mol % benzene. The reflux ratio is set at 4.0:1. Calculate the kg mol/h distillate D and bottoms W and their compositions. Also, calculate the number of theoretical plates required.