Which of the following molecules is/are polar

  1. $\ce{B3N3H6}$
  2. Hydroquinone
  3. Benzene
  4. $\ce{IF7}$

Molecules (4),(3) are non-polar. Molecule (4) has pentagonal bipyramidal structure and the dipole moments of \ce{I - F}$ Bonds cancel out.

I thought the answer was (1) (inorganic benzene). But the answer given is (2). How is hydroquinone or para-hydroxyphenol polar?

  • $\begingroup$ I find the term "polar" somewhat confusing. They all are polar, except benzene, but some have zero dipole moment. $\endgroup$ – Ivan Neretin Feb 24 '16 at 5:50