Intermolecular Forces is one of 9 topics in the Grade 11 Physical Sciences CAPS syllabus, covered across 3 lessons on Study Vault. Below are real practice questions from this topic with full worked answers.
Sample practice questions
Easy
1. Intermolecular forces are best described as:
The forces of attraction that act between neighbouring molecules
The forces that hold atoms together within a single molecule
Another name for covalent bonds
Forces that only exist inside a single atom
Answer: The forces of attraction that act between neighbouring molecules — Intermolecular forces act between separate molecules, and are distinct from (and much weaker than) the intramolecular covalent bonds within a molecule.
Easy
2. Which type of intermolecular force occurs between all molecules, including non-polar ones?
London (dispersion) forces
Hydrogen bonding only
Ion-dipole forces only
No intermolecular forces occur between non-polar molecules
Answer: London (dispersion) forces — London (dispersion) forces, arising from temporary induced dipoles, occur between all molecules, including non-polar ones, and are the only intermolecular force present in purely non-polar substances.
Medium
3. Hydrogen bonding requires a hydrogen atom covalently bonded directly to which type of atom?
A small, highly electronegative atom: nitrogen, oxygen, or fluorine
Any atom at all, regardless of electronegativity
Only carbon
Only atoms with a negative overall charge
Answer: A small, highly electronegative atom: nitrogen, oxygen, or fluorine — Hydrogen bonding specifically requires H covalently bonded to N, O, or F, which are small and highly electronegative, creating a strong enough dipole for this special, stronger dipole-dipole interaction.
