Which statement best describes hydrogen bonding in hydrogen fluoride (HF)?

Which statement best describes hydrogen bonding in hydrogen fluoride (HF)?

• A. Partial charges cause them to stick together
• B. HF molecules cannot hydrogen bond
• C. HF does not form hydrogen bonds
• D. Hydrogen bonds require metals

Answer: (A)

Hydrogen bonding in HF comes from a strong dipole created by fluorine pulling electron density away from hydrogen. This makes hydrogen carry a partial positive charge and fluorine a partial negative charge. The partially positive hydrogen of one HF molecule is attracted to the lone pairs on the fluorine of a neighboring HF molecule, forming a hydrogen bond. Because of these dipole-driven attractions, HF molecules stick together more than they would by simple dispersion forces. In short, the partial charges on HF molecules drive the intermolecular attraction that is characteristic of hydrogen bonding. Metals aren’t involved in this type of bonding, and HF can indeed form hydrogen bonds, so those statements aren’t correct.

Hydrogen bonding in HF comes from a strong dipole created by fluorine pulling electron density away from hydrogen. This makes hydrogen carry a partial positive charge and fluorine a partial negative charge. The partially positive hydrogen of one HF molecule is attracted to the lone pairs on the fluorine of a neighboring HF molecule, forming a hydrogen bond. Because of these dipole-driven attractions, HF molecules stick together more than they would by simple dispersion forces. In short, the partial charges on HF molecules drive the intermolecular attraction that is characteristic of hydrogen bonding. Metals aren’t involved in this type of bonding, and HF can indeed form hydrogen bonds, so those statements aren’t correct.