Question

The incorrect statement regarding the geometrical isomers of 2-butene is:

• A. cis-2-butene and trans-2-butene are not interconvertible at room temperature.
• B. cis-2-butene has less dipole moment than trans-2-butene.
• C. trans-2-butene is more stable than cis-2-butene.
• D. cis-2-butene and trans-2-butene are stereoisomers.

Answer 1

Answer: (B)

cis-2-butene has less dipole moment than trans-2-butene.

Answer 2

The structures of cis-2-butene and trans-2-butene are as follows:

cis-2-butene: $\text{CH}_3 - \text{CH} = \text{CH} - \text{CH}_3$ (Polar)
trans-2-butene: $\text{H} - \text{CH} = \text{CH} - \text{CH}_3$ (Non-Polar)

Cis-but-2-ene has a higher dipole moment than trans-but-2-ene due to the arrangement of the substituent groups. The cis configuration results in a net dipole moment, while the trans configuration cancels out the dipole due to symmetry.