A Level Chemistry OCR Practice Exam

Which of the following is NOT a type of intermolecular force?

1. Van der Waals forces

2. Hydrogen bonds

3. Ion-dipole forces

4. Magnetic forces

The correct answer is: Magnetic forces

The correct answer is magnetic forces, as they are not considered a type of intermolecular force. Intermolecular forces are the attractive forces that exist between molecules and are responsible for properties such as boiling points, melting points, and solubility. Van der Waals forces, which encompass London dispersion forces and dipole-dipole interactions, arise from temporary fluctuations in electron density, leading to induced dipoles in neighboring molecules. Hydrogen bonds are a specific type of dipole-dipole interaction, occurring when hydrogen is bonded to highly electronegative atoms like nitrogen, oxygen, or fluorine, resulting in a significantly stronger attraction. Ion-dipole forces occur between ions and polar molecules, playing a crucial role in the solvation of ions in solutions. These forces help in explaining the behavior of ionic compounds in solvents. Magnetic forces, however, are related to the interactions between magnetic fields and magnetic materials and do not contribute to the attractive forces between molecules, distinguishing them from the other types listed.