Question

22 multiple answer 2 points which of the following describe characteristics of (e)/(z) isomers? they have identical physical properties they differ in the arrangement of groups around a double bond. they are a type of stereoisomerism found in alkenes. they are non - superimposable mirror images.

Explanation:

• For option B: (E)/(Z) isomers (also known as cis - trans isomers for simple cases) are defined by the different spatial arrangements of groups around a carbon - carbon double bond. For example, in 2 - butene, the (Z) isomer (cis - 2 - butene) has the two methyl groups on the same side of the double bond, and the (E) isomer (trans - 2 - butene) has them on opposite sides.
• For option C: Stereoisomerism is a form of isomerism where isomers have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three - dimensional orientations of their atoms in space. (E)/(Z) isomerism is a specific type of stereoisomerism that occurs in alkenes due to the restricted rotation around the carbon - carbon double bond.
• For option A: (E)/(Z) isomers have different physical properties. For instance, cis - 2 - butene has a higher boiling point (\(3.7^{\circ}C\)) than trans - 2 - butene (\(0.9^{\circ}C\)) because the cis isomer has a higher dipole moment and stronger intermolecular forces (dipole - dipole interactions in addition to London dispersion forces).
• For option D: Non - superimposable mirror images are a characteristic of enantiomers (a type of optical isomerism), not (E)/(Z) isomers. (E)/(Z) isomers are diastereomers (stereoisomers that are not mirror images of each other).

Answer:

B. They differ in the arrangement of groups around a double bond.
C. They are a type of stereoisomerism found in alkenes.