* Note: Problems on mass spectroscopy are not in this section but instead in the spectroscopy section.

1.* (1996 F 14) Which of the following separation methods use an external electric field to cause the separation: solvent extraction, mass spectroscopy, liquid chromatography, electrophoresis, centrifugation.

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2. A. Could you separate a mixture of enantiomers based on their physical properties?

B. Could you tell the difference between two enantiomers based on their NMR spectra? Their UV-vis spectra? Their IR or Raman spectra? Their gas chromatograph? Their mass spectra?

C. Is there any way to separate enantiomers other than making the diastereomeric salt and then exploiting the different physical properties of the two diastereomers? If so, explain how your technique would work.

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3.* (1996 2 8)
Note: the same problem worded slightly differently also appeared on the 2nd exam of 1993. It’s a popular problem . . .
What is the value of the minimum partition coefficient K, defined as K = [A]org/[A]aq that would permit removal of 99% of a solute A from 50.0 mL of water with two 20.0 mL extractions with toluene?

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