The specific rotation of (R)-(+)-glyceraldehyde is +8.7. If the observed specific rotation of a mixture of (R)-glyceraldehyde and (S)-glyceraldehyde is +1.4, what percent of glyceraldehyde is present as the R enantiomer?

A solution of an unknown compound (3.0 g of the compound in 200 mL of solution), when placed in a polarimeter tube 2.0 dm long, was found to rotate the plane of polarized light 18° in a counterclockwise direction. What is the specific rotation of the compound?

Indicate whether each of the following structures is (R)-2-chlorobutane or (S)-2-chlorobutane:

c.

d.

Are the following pairs identical, enantiomers, diastereomers, or constitutional isomers?

c.

d.

Citrate synthase, one of the enzymes in the series of enzyme-catalyzed reactions known as the citric acid cycle, catalyzes the synthesis of citric acid from oxaloacetic acid and acetyl-CoA. If the synthesis is carried out with acetyl-CoA that contains radioactive carbon (14C) in the indicated position, the isomer shown here is obtained.

b. If the acetyl-CoA used in the synthesis contains 12C instead of 14C, will the product of the reaction be chiral or achiral?

Indicate whether each of the following structures is (R)-2-chlorobutane or (S)-2-chlorobutane:

a.

b.

Indicate whether each of the following structures is (R)-2-chlorobutane or (S)-2-chlorobutane:

e.

f.