Question

The molecules that will have dipole moments are:

• A. $1,2$-dichloro benzene
• B. cis-$3$-hexene
• C. trans-$2$-pentene
• D. All of these

Answer 1

The correct option is D All of these

All of them has some dipole moment.
$1,2$-dichloro benzene is certain angle(<180) between the two chlorine, hence dipole exist. Same is the case with cis-$3$-hexene.
trans-$2$-pentene: here we have two different groups attached at trans position, hence dipole exist. Dipole would have been zero, if two same groups are at trans position.