Dipole-dipole interactions apply to which type of molecules?

Dipole-dipole interactions apply to which type of molecules?

• A. Ionic compounds
• B. Nonpolar molecules
• C. Polar, non-ionic molecules that do not have an H bonded to an O, N, F
• D. Metals

Answer: (C)

Dipole-dipole interactions occur when molecules have a permanent dipole moment due to differences in electronegativity, giving one end a partial negative charge and the other a partial positive charge. These forces act between neighboring polar molecules (covalently bonded but not ionic) because the positive end of one molecule is attracted to the negative end of another. Ionic compounds aren’t described by dipole-dipole forces—they’re held together by strong electrostatic attractions between ions. Metals rely on metallic bonding, not dipoles. Nonpolar molecules lack a permanent dipole, so they don’t participate in dipole-dipole attractions and are dominated by London dispersion forces. Hydrogen bonding is a special strong form of dipole-dipole interaction that requires H bonded to O, N, or F, which is why the general dipole-dipole concept is most straightforwardly described for polar, non-ionic molecules that don’t rely on those specific H–bond donors.

Dipole-dipole interactions occur when molecules have a permanent dipole moment due to differences in electronegativity, giving one end a partial negative charge and the other a partial positive charge. These forces act between neighboring polar molecules (covalently bonded but not ionic) because the positive end of one molecule is attracted to the negative end of another. Ionic compounds aren’t described by dipole-dipole forces—they’re held together by strong electrostatic attractions between ions. Metals rely on metallic bonding, not dipoles. Nonpolar molecules lack a permanent dipole, so they don’t participate in dipole-dipole attractions and are dominated by London dispersion forces. Hydrogen bonding is a special strong form of dipole-dipole interaction that requires H bonded to O, N, or F, which is why the general dipole-dipole concept is most straightforwardly described for polar, non-ionic molecules that don’t rely on those specific H–bond donors.