Which type of intermolecular force would be the hardest to overcome during boiling?

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

Answer: (A)

Verified step by step guidance

1. Understand that boiling a substance requires overcoming the intermolecular forces holding its molecules together in the liquid phase.
2. Identify the types of intermolecular forces listed: hydrogen bonding, dipole-dipole interactions, ion-dipole interactions, and London dispersion forces.
3. Recall the relative strengths of these forces: London dispersion forces are the weakest, dipole-dipole interactions are stronger, hydrogen bonding is stronger than dipole-dipole, and ion-dipole interactions are generally very strong but occur in mixtures of ions and polar molecules.
4. Since the question is about boiling a pure substance (implied), ion-dipole interactions are less relevant because they involve ions and polar molecules, not just molecules of one substance.
5. Conclude that hydrogen bonding is the strongest intermolecular force among the options that typically exist in pure molecular substances, making it the hardest to overcome during boiling.