Which type of intermolecular force is present in CH_4 (methane)?

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

Answer: (D)

Verified step by step guidance

1. Identify the molecular structure and polarity of CH_4 (methane). Methane is a tetrahedral molecule with four C-H bonds, which are considered nonpolar due to the small difference in electronegativity between carbon and hydrogen.
2. Determine if the molecule has a permanent dipole moment. Since CH_4 is symmetrical and nonpolar, it does not have a permanent dipole moment, so dipole-dipole interactions are not present.
3. Check for hydrogen bonding. Hydrogen bonding occurs when hydrogen is directly bonded to highly electronegative atoms like nitrogen, oxygen, or fluorine. In CH_4, hydrogen is bonded to carbon, so hydrogen bonding is not possible.
4. Consider ion-dipole interactions. These occur between ions and polar molecules. Since CH_4 is nonpolar and not an ion, ion-dipole interactions do not apply.
5. Conclude that the only intermolecular forces present in CH_4 are London dispersion forces, which are weak forces arising from temporary fluctuations in electron distribution in nonpolar molecules.