Which type of intermolecular force is primarily responsible for interactions between nonpolar molecules?

• A. Dipole-dipole interactions
• B. London dispersion forces
• C. Ion-dipole forces
• D. Hydrogen bonding

Answer: (B)

Verified step by step guidance

1. Identify the nature of the molecules involved: nonpolar molecules have no permanent dipole moment because their electron distribution is symmetrical.
2. Recall that dipole-dipole interactions occur between molecules with permanent dipoles, so they are not the main force between nonpolar molecules.
3. Understand that hydrogen bonding is a special, strong type of dipole-dipole interaction that requires hydrogen bonded to highly electronegative atoms (N, O, or F), which is not present in nonpolar molecules.
4. Recognize that ion-dipole forces involve interactions between ions and polar molecules, so they do not apply to nonpolar molecules.
5. Conclude that the primary intermolecular force between nonpolar molecules is London dispersion forces, which arise from temporary fluctuations in electron density creating instantaneous dipoles that induce dipoles in neighboring molecules.