AP Exam Prep
Pick a unit, answer 113 original questions across the course, and see exactly which topics need work. Every test is free, scored instantly and explained question by question. No sign-up needed.
A practice test is most useful when it tells you what to do next. Each StudyCoach unit test shows you:
Every question is tagged with a topic from the course framework, so you see which topics are strong and which need work.
Explanations cover the correct answer and the reasoning behind the tempting wrong ones.
Mark how sure you are as you answer. Questions you guessed right, or got wrong while sure, are worth reviewing first.
Mistake Detective separates one-off slips from repeated patterns, targeted practice gives you new questions on your weak topics (each answer key checked by a second, independent AI pass), you can ask for any explanation in a different way, and a revision plan weighs each unit against your exam date. See pricing
The 2027 exam is on Thursday 6 May 2027. It has two sections of equal weight.
| Unit | Weighting | Class periods |
|---|---|---|
| 1. Atomic Structure and Properties | 7–9% | ~9–10 |
| 2. Compound Structure and Properties | 7–9% | ~12–13 |
| 3. Properties of Substances and Mixtures | 18–22% | ~14–15 |
| 4. Chemical Reactions | 7–9% | ~14–15 |
| 5. Kinetics | 7–9% | ~13–14 |
| 6. Thermochemistry | 7–9% | ~10–11 |
| 7. Equilibrium | 7–9% | ~13–15 |
| 8. Acids and Bases | 11–15% | ~14–16 |
| 9. Thermodynamics and Electrochemistry | 7–9% | ~10–13 |
Source: College Board, AP Chemistry Course at a Glance and course overview.
Use this as a checklist. Each unit page has the full topic list, key ideas, common mistakes and its practice test.
Unit 1 connects counting particles to the structure of atoms. You need to convert between mass, moles and particles, read mass spectra and photoelectron spectra, and explain periodic trends with Coulomb's law.
Focus on: the mole links mass and particles; composition reveals formulas; electrons fill shells and subshells; coulomb's law explains trends.
Unit 2 explains how atoms are held together and how that shapes a substance. Expect questions on bond type, lattice strength, alloys, Lewis structures, resonance and molecular shape.
Focus on: bond type follows electronegativity; potential energy sets bond length; ionic and metallic structures; lewis structures predict shape.
Unit 3 has the largest exam weighting. It explains how forces between particles decide boiling points, gas behaviour and solubility, and how light is used to measure concentration.
Focus on: intermolecular forces decide properties; gases follow pv = nrt; solutions and separations; light and concentration.
Unit 4 is about writing, balancing and calculating with reactions. Most questions ask you to use a balanced equation's mole ratio, write a net ionic equation or classify a reaction.
Focus on: balanced equations give mole ratios; net ionic equations show what changes; titration finds unknown amounts; acid–base and redox.
Unit 5 asks how fast reactions happen and why. You will find rate laws from data, use integrated rate laws and half-life, and connect mechanisms and energy profiles to the observed rate law.
Focus on: rate laws come from experiments; concentration over time; collisions and activation energy; mechanisms explain rate laws.
Unit 6 tracks energy in physical and chemical changes. You will calculate heat with q = mcΔT, find enthalpy changes from bond enthalpies, formation data and Hess's law, and read energy diagrams.
Focus on: exothermic and endothermic; calorimetry; three ways to find δh; phase changes.
Unit 7 explains what happens when forward and reverse reactions balance. You will write and calculate K and Q, predict shifts with Le Châtelier's principle and work with solubility equilibria.
Focus on: equilibrium is dynamic; k and q; manipulating k; le châtelier and solubility.
Unit 8 is the second most heavily weighted unit. You will calculate pH for strong and weak acids and bases, explain buffers and titration curves, and connect molecular structure to acid strength.
Focus on: ph of strong and weak species; buffers resist ph change; titration curves; structure and strength.
Unit 9 asks whether a process is thermodynamically favourable and how that energy can be harnessed. You will use entropy, ΔG = ΔH − TΔS, the link between ΔG° and K, and electrochemical cells.
Focus on: entropy and free energy; favourable isn't always fast; δg° and k; electrochemical cells.
Yes. Every unit test is free, needs no account, and shows the correct answer with a worked explanation for every question, including why each wrong option is tempting. Premium adds coaching on your mistakes, such as finding the exact step where your working went wrong.
No. StudyCoach wrote original questions mapped to the College Board's current AP Chemistry course framework. They practise the same topics and skills, but they are not released exam questions.
Yes. Unit names and topics follow the College Board's current course framework, including Unit 3 (Properties of Substances and Mixtures), Unit 6 (Thermochemistry) and Unit 9 (Thermodynamics and Electrochemistry).
Yes. A calculator is allowed on the AP Chemistry exam, and you'll want one for the calculation questions here. Explanations show each step with units so you can check your own working.
Your scores are saved in this browser so you can track progress across units. They aren't linked to your StudyCoach account yet, so clearing your browser data removes them.
Not yet. These tests are multiple choice. Free-response practice is planned.
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