Separations and purifications: Extraction to separate benzene derivatives

In an experiment for undergraduate chemistry students, 4-chlorobenzoic acid and 4-bromoaniline may be separated through extraction with the addition of H2O, diethyl ether, and NaOH in the appropriate order. Initially, 4-bromoaniline and 4-chlorobenzoic acid were dissolved in ether. A second reagent was added, and after mixing the reagents and allowing the layers to separate, two layers were observed: Layer A and Layer B. The two layers were separated from one another and hydrochloric acid was added in order to recover 4-chlorobenzoic acid from Layer B. Finally, anhydrous magnesium sulfate was used as a drying agent.

The densities and boiling points of these reagents were measured and are listed in the following table.