Dihydroxybenzene, C6H6O2, exists in three forms (isomers) called ortho, meta, and para:

Which of these has a nonzero dipole moment?

Key Concepts

Isomerism

Isomerism refers to the phenomenon where compounds have the same molecular formula but different structural arrangements. In the case of dihydroxybenzene, the ortho, meta, and para isomers differ in the positions of the hydroxyl (-OH) groups on the benzene ring, leading to distinct physical and chemical properties, including dipole moments.

Dipole Moment

A dipole moment is a measure of the separation of positive and negative charges in a molecule, indicating its polarity. Molecules with a nonzero dipole moment have an uneven distribution of electron density, resulting in a positive and a negative end. The orientation and arrangement of functional groups in isomers can significantly affect their dipole moments.

Molecular Geometry

Molecular geometry describes the three-dimensional arrangement of atoms within a molecule. The spatial arrangement of atoms in ortho, meta, and para isomers of dihydroxybenzene influences their dipole moments. For instance, the ortho and meta isomers can exhibit nonzero dipole moments due to their asymmetrical structures, while the para isomer is symmetrical and typically has a zero dipole moment.