Challenging! Develop a spreadsheet with VBA to solve the following problem. A simple batch distillation of the system n-butane, n-pentane, and n-hexane is planned. \(1.0 \mathrm{kmol}\) of a feed that is initially \(45 \mathrm{~mol} \% \mathrm{n}\) butane, \(45 \mathrm{~mol} \% \mathrm{n}\)-pentane, and \(10 \mathrm{~mol} \% \mathrm{n}\)-hexane is to be distilled until \(0.05 \mathrm{kmol}\) remains in the still pot. Find the concentration of the liquid remaining in the still pot, the average distillate concentration, and the amount of the distillate.

A bare minimum of instructions on writing and running VBA programs in an Excel spreadsheet are presented in the Appendix to Chapter 19.