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Unit 3: Lesson 1

Chemical and physical sciences practice passage questions

Separations and purifications - Passage 2


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.
Density (g/cm3)Boiling point (°C)
Diethyl ether0.73434.6
4-Chlorobenzoic acid1.374275
If water and ether are in the extraction, water will be:
Choose 1 answer:
Choose 1 answer: