Question

Which has highest dipole moment?

• A. $2,2$-dimethyl propane
• B. trans-$2$-pentene
• C. cis-$3$-hexene
• D. $2,2,3,3$-tetramethyl butane

Answer 1

Answer: (C)

cis-$3$-hexene

$2,2$-dimethyl propane and $2,2,3,3$-tetramethyl butane are symmetrical alkanes. They have zero dipole moment.

The dipole moment of cis-$3$-hexene is maximum as the dipole moment of cis alkene is higher than trans alkene.

In symmetrical trans alkene, the dipole moment is zero due to symmetry.

Trans-$2$-pentene is unsymmetrical trans alkene and has some dipole moment. But its dipole moment is lower than that of cis-$3$-hexene.