Organic Chemistry Quiz on Stereochemistry

Which of the following statements is true?

• All molecules that have stereocenters are chiral

• Superposable structural isomers are enantiomers

• All mirror images are enantiomers

• Isomers that are not superposable on their mirror images are enantiomers

Which of the following is the definition of a meso compound?

• A diastereomer with no stereocenters

• A chiral compound with more than one stereocenter

• A molecule with stereocenters which is not chiral

• A molecule with stereocenters which is chiral

How many stereoisomers of 2,3-butanediol exist?

• 1

• 4

• 2

• 3

A solution containing 0.2 g/mL of a pure R enantiomer in a 1 dm polarimeter rotates plane polarized light by +3°. What is the specific rotation of the R isomer?

• +15°

• +150°

• +0.06°

• +67°

What is the enantiomeric excess (%ee) of a mixture that rotates plane polarized light by -3° in a 1 dm polarimeter, given that the R-enantiomer has a specific rotation of -15°?

• 75% R

• 33% S

• 50% R

• 33% R