Which intermolecular force involves a hydrogen atom bonded to a highly electronegative atom being attracted to a lone pair on another electronegative atom in a nearby molecule?

• A. London dispersion forces
• B. Dipole
• C. Solvent
• D. Hydrogen bonding

Answer: (D)

Hydrogen bonding is a strong, specific type of intermolecular attraction that occurs when a hydrogen atom is covalently bonded to a highly electronegative atom (such as nitrogen, oxygen, or fluorine) and is attracted to a lone pair on another electronegative atom in a nearby molecule. The small, highly positive hydrogen can approach closely to the lone pair on the other molecule, creating a relatively strong dipole–dipole interaction. This is the reason water exhibits unusually high boiling point and a strong solvent behavior for many substances, and why alcohols and amines often show pronounced hydrogen-bonding effects.

London dispersion forces are present in all molecules but are generally weaker and arise from momentary dipoles. A generic dipole interaction refers to any dipole–dipole attraction, but hydrogen bonding is a special case that requires the X–H bond and a lone pair on an electronegative partner, making it particularly strong. A solvent is a substance, not a type of intermolecular force, so that option isn’t describing an interaction.