1. It is required to separate 200 lb-mols/h or a 40% benzene and 60% toluene mixture into a top product containing 95% benzene and a bottom stream containing 90% toluene. The feed mixture is 25% vaporized. The reflux ratio is 3:1, and a total condenser is to be used.
a. How many theoretical stages are required?
b. At what stage should the feed be introduced?