Question

Bromine is less electronegative than chlorine, yet methyl bromide and methyl chloride have very similar dipole moments. why? select the single best answer.

Answer 1

Bromine is less electronegative than chlorine, yet methyl bromide and methyl chloride have very similar dipole moments. This is because the bond distance in methyl bromide is more due to the large size of bromine atom.
Dipole moment is calculated by multiplying the charge on the atom with the bond distance.