2. A distillation column with a total condenser and a partial reboiler is separating a mixture that is 40 mole \% n-butane and 60 mole %n-hexane. The feed to the column is saturated liquid. Feed flow rate is 100kmoles/hr. Reflux is returned as saturated liquid and boilup is returned as saturated vapour. Desired distillate composition is 90 mole %n butane and desired bottoms composition is 4 mole \% n-butane. Constant molal overflow maybe assumed. Use the McCabe Thiele diagram provided. i) Plot the feed line in the McCabe Thiele diagram provided. ii) For an actual reflux ratio of R=1.5Rmin, find the total number of stages needed and the optimum feed stage