Which molecule is a stereoisomer of cis-2-pentene?
The Correct Answer and Explanation is :
The molecule that is a stereoisomer of cis-2-pentene in the image you provided is trans-2-pentene.
Explanation
Stereoisomers are molecules that have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in space. This includes cis-trans isomers, which are types of geometric isomers where the substituents differ in their position relative to a double bond or a ring structure, specifically on either the same side (cis) or opposite sides (trans).
- Cis-2-pentene has both methyl groups on the same side of the double bond. In the image, cis-2-pentene would have the two CH₃ groups both on the top or both on the bottom of the carbon chain at the double bond located at the second carbon.
- Trans-2-pentene, a stereoisomer of cis-2-pentene, has the two methyl groups on opposite sides of the double bond. This structural arrangement leads to different physical and chemical properties between the cis and trans forms.
- Cis-isomers, like cis-2-pentene, generally have higher boiling points due to stronger Van der Waals forces (the result of the polarizability of the molecule being more effective when the larger groups are on the same side).
- Trans-isomers, like trans-2-pentene, tend to have lower boiling points and are often less polar than their cis counterparts.
The distinction in their physical properties arises because the spatial arrangement affects the overall shape of the molecule, which in turn influences molecular interactions such as dipole-dipole attractions and steric hindrance.
For visual aid, I will generate an image of trans-2-pentene, which is a stereoisomer of cis-2-pentene, to illustrate the difference in their molecular structures more clearly.
Here is the illustration of the molecule trans-2-pentene, which demonstrates the trans configuration with methyl groups on opposite sides of the double bond. This image should help visualize the structural difference from its cis counterpart.
