Question

Why para methoxy benzene hhas dipole moment?

Answer 1

(a) there are no appreciable mesomeric interactions between the polar groups in the molecule
(b) evidence is obtained for the hindered rotation of the OH and OCH3, groups
(c) the difference between the dipole moments of the title compounds and those of the corresponding benzene derivatives can be referred both to the extension of the conjugated system and to the value of the interaction moment