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natural product isolation experiment, multiple extractions of the aqueous tea ex

ID: 888494 • Letter: N

Question

natural product isolation experiment, multiple extractions of the aqueous tea extract with methylene chloride are required to maximize the yield of caffeine. Why?

the partition coefficient is such that nearly all of the caffeine is extracted into the organic phase after only one extraction

caffeine is not soluble in methylene chloride

the partition coefficient is such that nearly all of the caffeine remains in the aqueous phase after only one extraction

the partition coefficient is such that a significant amount of caffeine remains in the aqueous phase after only one extraction

A.

the partition coefficient is such that nearly all of the caffeine is extracted into the organic phase after only one extraction

B.

caffeine is not soluble in methylene chloride

C.

the partition coefficient is such that nearly all of the caffeine remains in the aqueous phase after only one extraction

D.

the partition coefficient is such that a significant amount of caffeine remains in the aqueous phase after only one extraction

Explanation / Answer

Answer: the partition coefficient is such that a significant amount of caffeine remains in the aqueous phase after only one extraction.

Explanation:

According to Nernst Distribution law a solute will distribute itself between two essentially immiscible solvents so that at equilibrium the ratio of the concentrations of the solute in the two phases at a particular temperature will be constant, provided the solute is not involved in chemical interactions in either phase ( book language).

Also, multiple extraction with same amount of solvent will remove more solute as compared to single extraction.