Which is the strongest type of intermolecular force present between CH_4 molecules?

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

Answer: (C)

Verified step by step guidance

1. Identify the molecular structure and polarity of CH_4 (methane). CH_4 is a tetrahedral molecule with four identical C-H bonds, and the molecule is nonpolar overall because the bond dipoles cancel out.
2. Recall the types of intermolecular forces: ion-dipole, dipole-dipole, hydrogen bonding, and London dispersion forces. Ion-dipole forces occur between ions and polar molecules, dipole-dipole forces occur between polar molecules, and hydrogen bonding requires a hydrogen atom bonded to N, O, or F.
3. Since CH_4 is nonpolar and contains no highly electronegative atoms bonded to hydrogen, it cannot exhibit ion-dipole, dipole-dipole, or hydrogen bonding interactions.
4. The only intermolecular force present in CH_4 molecules is London dispersion forces, which arise from temporary fluctuations in electron density creating instantaneous dipoles even in nonpolar molecules.
5. Therefore, the strongest intermolecular force in CH_4 is London dispersion forces.