Consider a system for heating a liquid benzene/toluene solution to distil a pure benzene vapour. A particular batch distillation unit is charged initially with 100 mol of a 60 percent mol benzene/40
percent mol toluene mixture. Let (mol) be the amount of liquid remaining in the still, and let (mol
B/mol) be the benzene mole fraction in the remaining liquid. Conservation of mass for benzene and
toluene can be applied to derive the following relation [Felder, 1986].
= 100 (

0.6
)
0.625 (
1 −
0.4
)
−1.625
Determine what mole fraction of benzene remains when = 70[mol]. Please present both
numerical and graphical solutions. Both results and show the percentage error of graphical solution
shall be presented by using disp or fprintf function