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JEE Main levelOne or more correct optionsDifficulty 2 of 3st128

A racemic carboxylic acid is treated with enantiomerically pure (R)-1-phenylethylamine to form salts. Select the correct statements.

  1. AThe two salts formed are diastereomers of each other
  2. BThe two salts formed are enantiomers of each other
  3. CThe two salts can be separated by fractional crystallisation
  4. DThe two salts must have identical solubilities in all solvents

Answer: A, C

The (R)-acid/(R)-amine salt and the (S)-acid/(R)-amine salt differ in configuration at only one of two stereocentres, so they are diastereomers. Diastereomers differ in physical properties such as solubility, so they can be separated by fractional crystallisation, after which each acid is liberated. Enantiomers would have identical solubilities.
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