CHEMISTRY COMMUNITY

Identify the types of attractive intermolecular interactions

that might arise between molecules of each of the following sub-
stances: (a) NH2OH; (b) CBr4; (c) H2SeO4; (d) SO2.

I understand a, b, and d but why does H2SeO4 have dipole-dipole interactions? I don't understand why it is a polar molecule.

The central Se atom is single bonded to two OH groups and double bonded to two O. The OH groups will be polar w/ partial positives on H and partial negatives on O. Also, since the electron distribution is different for the single and double bonds, some areas on the molecule will “concentrate” more electrons than others.