CHEMISTRY · Single correct · A Level · Chemistry · Chromatography · Chromatography
Problem
A liquid mixture consists of benzene (bp 80 °C, non-polar), water (bp 100 °C, highly polar), and a non-volatile green dye that is moderately polar. The objective is to obtain each component separately in pure form while using the LEAST amount of energy. Which of the following operation sequences would best accomplish this task?
(a) Separate the green dye from the liquid mixture by column chromatography, then use fractional distillation on the eluate to separate benzene and water.
(b) Simple distillation to remove benzene first, steam distillation of the residue to collect water, then column chromatography of the remaining solid to isolate the green dye.
(c) Vacuum filtration of the mixture to remove the dye, followed by azeotropic distillation to separate benzene and water.
(d) Fractional distillation of the mixture to collect benzene, followed by liquid–liquid extraction of the residue to remove water, leaving the dye behind.