Question

Which of the following pairs of structures represents a pair of enantiomers?

a) (R)-2-bromobutane and (S)-2-bromobutane
b) (Z)-2-butene and (E)-2-butene
c) cis-1,2-dichloroethene and trans-1,2-dichloroethene
d) 1,1-dichloroethane and 1,2-dichloroethane

Answer 1

The pair of enantiomers is (R)-2-bromobutane and (S)-2-bromobutane.

Step-by-step explanation:

Enantiomers are stereoisomers that are mirror images of each other and cannot be superimposed. In order for two structures to be enantiomers, they must have the same connectivity of atoms but differ in the spatial arrangement of substituent groups.

Out of the given options, the pair of structures that represents a pair of enantiomers is (a) (R)-2-bromobutane and (S)-2-bromobutane. These two structures have the same formula and connectivity, but differ in the arrangement of the bromine atom and the butyl group, making them enantiomers.