Vapor-liquid equilibrium data at 760 mmHg were determined for the quaternary ethanol-isopropanol-ethyl acetate-isopropyl acetate system. Following hypothetical reaction is considered for the quaternary system.
EtOH+AcOiPr^→_←iPrOH+AcOEt The system could be treated as a system accompanied by chemical reaction. That is, vapor-liquid equilibria for the quaternary system could be calculated from the vapor-liquid equilibrium data for the binary and ternary systems at conversion 0 or 1. Similar results were obtained for the methanol-ethanol-methyl acetate-ethyl acetate system.