What’s on the AP Chemistry Exam? A Complete Breakdown

Knowing the structure of the test you're walking into is half the battle. Too many students go into the AP Chemistry exam with only a vague sense of what's coming, and that uncertainty costs them points. Not because they don't know the chemistry, but because they don't know how to allocate their time or what format their answers need to take. Here's the full picture, so you can walk in prepared.

The structure.

Two sections. Section I is 60 multiple-choice questions in 90 minutes, worth 50% of your total score. Section II is 7 free-response questions in 105 minutes, also worth 50%. A scientific or graphing calculator is permitted on both sections. You'll receive a periodic table and a formula sheet with key equations and constants, so you don't need to memorize things like PV = nRT or the Nernst equation. But having the formulas in front of you is not the same as knowing when and how to use them. The students who score well are the ones who've practiced with the reference sheet enough that they can find and apply the right equation without wasting time.

The 9 units and their approximate exam weight.

Units 1–3 cover Atomic Structure and Properties, Molecular and Ionic Compound Structure and Properties, and Intermolecular Forces and Properties. Together these account for roughly 20% of the exam. These are the foundational units: important, but not where most of the exam points live.

Units 4–6 cover Chemical Reactions, Kinetics, and Thermodynamics, accounting for roughly 35% of the exam. This is where the computational intensity picks up and where many students start to feel the difficulty curve steepen.

Units 7–9 cover Equilibrium, Acids and Bases, and Applications of Thermodynamics (including Electrochemistry). Together these account for roughly 45% of the exam, nearly half. Notice the trend: the back half of the course is tested significantly more heavily than the front half. Students who cruise through first semester and hit a wall in the second are in serious trouble come May. If you're going to invest extra study time anywhere, Units 7–9 give you the highest return on investment.

What the MCQ section actually tests.

Conceptual understanding, data interpretation, and particulate-level reasoning. There are fewer pure calculation problems than most students expect; the College Board has been trending away from straightforward plug-and-chug for years. A typical question might show a particulate diagram and ask which change would shift the equilibrium, or present a graph of reaction rate versus concentration and ask you to determine the rate law, or give you two titration curves and ask which represents the stronger acid. If you're not comfortable reading figures and interpreting graphical data under time pressure, practice that skill specifically. It's worth more than memorizing another set of equations.

What the FRQ section demands.

Multi-step calculations with fully shown work, experimental design and error analysis, particulate-level diagrams, and extended reasoning about equilibrium, thermodynamics, and kinetics. The 7 FRQs break down as 3 long questions (10 points each) and 4 short questions (4 points each). Every long FRQ requires calculations, written justifications, and usually a drawn representation of some kind. The short questions are tighter, typically one calculation and one justification, or a diagram with an explanation. See Post 2 for a detailed breakdown of rubric strategy, including the specific language that earns (and doesn't earn) points.

Scoring context.

In recent years, roughly 13–16% of test-takers scored a 5, and about 18–20% scored a 4. A composite score around 70–75% of the maximum typically earns a 5, though the exact cutoff varies by year. You don't need perfection; you need consistent point-earning across both sections. A student who earns solid partial credit on every FRQ and answers 45 out of 60 MCQs correctly is in strong 5 territory. The students who get 5s aren't the ones who know everything; they're the ones who know how to earn points efficiently.

Strategic advice for exam day.

On the MCQ section, don't spend more than 90 seconds on any single question during your first pass. Mark anything that requires extended thought and come back to it. There's no penalty for wrong answers, so never leave a question blank. If you're out of time, guess. Statistically, even random guessing picks up a few points, and educated elimination can push that significantly higher.

On the FRQ section, read every part of a multi-part question before you start writing. Later parts sometimes give hints about earlier parts. For example, part (d) might reference a value you should have calculated in part (b), confirming your approach. Budget your time: roughly 20 minutes per long question and 8–10 minutes per short question. If you get stuck on a calculation, write the setup with correct units and move on; the setup points are often worth more than the numerical answer.