Which is the predominant intermolecular force present in NaCl(aq)?

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

Answer: (C)

Verified step by step guidance

1. Identify the components in the solution: NaCl dissolved in water (aqueous solution). NaCl dissociates into Na⁺ and Cl⁻ ions in water.
2. Recall the types of intermolecular forces: hydrogen bonding occurs between molecules with H bonded to N, O, or F; dipole-dipole interactions occur between polar molecules; London dispersion forces are present in all molecules but are weakest; ion-dipole interactions occur between ions and polar molecules.
3. Since NaCl dissociates into ions (Na⁺ and Cl⁻) and water is a polar molecule with a permanent dipole, consider the interaction between these ions and the polar water molecules.
4. Recognize that the strongest and predominant intermolecular force in this system is the ion-dipole interaction, which arises from the attraction between the charged ions and the partial charges on the water molecules.
5. Conclude that among the given options, ion-dipole interactions are the predominant intermolecular force in an aqueous NaCl solution.