Intermolecular Forces and Properties unit test

A test on this unit alone, marked as a percentage and a letter grade — for the test your class is actually sitting, rather than for May. Answer everything, then submit once: seeing the answer to question 3 before attempting question 4 makes the final percentage meaningless.

Paper 1 Paper 2 Paper 3

Each paper is built from this unit’s 22 terms and is the same for everyone, so a teacher can assign “Unit 3, Paper 1” and every student sits the identical test. Multiple choice is marked objectively; the written sections you mark yourself against the model answer and rubric.

Suggested time 31 min 28 points0/17 attempted

Real gas deviation direction

Boiling point and IMF strength

Partial pressure and Dalton's law

Kinetic molecular theory assumptions

Maxwell-Boltzmann distribution

Molarity

Surface tension and viscosity

Distillation

Solubility and "like dissolves like"

Chromatography

Beer-Lambert law

Effusion and Graham's law

Short answer 1. Define or explain: London dispersion forces

3 pts

Short answer 2. Define or explain: Hydrogen bonding

3 pts

Short answer 3. Define or explain: Comparing boiling points correctly

3 pts

Short answer 4. Define or explain: Why intermolecular forces are weaker than bonds

3 pts

Free response

4 pts

A student compares the boiling points of three substances of similar molar mass: propane (C₃H₈, 44.1 g/mol, bp −42 °C), acetaldehyde (CH₃CHO, 44.1 g/mol, bp 20 °C), and ethanol (C₂H₅OH, 46.1 g/mol, bp 78 °C).

(a) Identify the dominant intermolecular force in each of the three substances.

(b) Explain the trend in boiling points using your answers to part (a).

(d) Predict how the boiling point of butane (C₄H₁₀, 58.1 g/mol) compares with that of propane, and justify your prediction.