AP Chemistry practice test: free questions, exam format and 2027 date

Each daily paper has 8 original free-response questions worth 25 to 35 marks. Together, the two papers above cover most of AP Chemistry. The Honors Chemistry paper covers moles, electron configuration, bonding and shapes, intermolecular forces, enthalpy, kinetics and equilibrium. The AP Chemistry paper covers acids, bases and buffers, rate laws, equilibrium, entropy and electrochemistry. Both also include organic reactions, and the AP Chemistry paper has NMR and transition metal chemistry. Those go beyond AP Chemistry, so skip them or treat them as extra.

Where to find a real AP Chemistry practice test

• Past free-response questions: College Board posts recent AP Chemistry free-response questions on AP Central, with scoring guidelines and sample student answers. Find them from the Exam Preparation section of the course's exam page.
• AP Classroom: your teacher can unlock progress checks with multiple-choice and free-response questions, and assign practice or released exam questions from the AP Question Bank.
• Bluebook test preview: download the Bluebook app to see how the digital exam works. College Board says previews for most AP subjects are available now, with more coming in early 2027.
• A short daily practice test: the papers above, for 35 to 45 minutes of timed free-response practice.

AP Chemistry exam format for 2027

The three long free-response questions are worth 10 points each and the four short ones 4 points each. It is a hybrid digital exam: you answer the multiple-choice questions and read the free-response questions in the Bluebook app, then handwrite your free-response answers in a paper booklet. College Board provides reference materials, such as equation sheets and reference tables.

You can use a scientific or graphing calculator on both sections, and Bluebook has a built-in Desmos calculator. A four-function calculator is allowed but not recommended. The pace is about 1.5 minutes per multiple-choice question, and roughly 20 minutes for each long free-response question and 10 for each short one.

AP Chemistry units and how much each is worth

Unit 3 is the biggest by far, at up to 22%, and acids and bases come next. College Board recommends high school chemistry and Algebra II before you start. The tools: Molar Mass, Electron Configuration, Chemical Bonding course, Molecule Builder, Gas Laws, Molarity, Equation Balancer, Stoichiometry, Reaction Kinetics course, Enthalpy, Rates and Equilibrium, pH and Titration Lab.

AP Chemistry practice test questions with answers

We wrote these five questions for this page. They follow the order of the course and rise in difficulty. Try each before reading the working, and keep your units in every line.

1. Stoichiometry: burning propane

Question: Propane burns completely: C₃H₈ + 5O₂ → 3CO₂ + 4H₂O. What mass of carbon dioxide forms from 11.0 g of propane?

The molar mass of propane is 44.09 g/mol, so 11.0 g is 0.2495 mol. The equation gives 3 mol of CO₂ for every mole of propane, so 0.7484 mol of CO₂ forms. At 44.01 g/mol, that is 32.9 g. Go grams to moles, use the mole ratio, then moles to grams. The Stoichiometry Calculator runs the same steps.

2. Gases: the ideal gas law

Question: 0.500 mol of an ideal gas is held in a 10.0 L container at 300 K. What is its pressure in atmospheres?

Pick the value of R that matches your units: 0.08206 L atm per mol K gives atmospheres when volume is in liters. Temperature must be in kelvin. Check other cases with the Gas Laws Calculator.

3. Kinetics: first-order half-life

Question: A first-order reaction has a rate constant of 0.0231 min⁻¹. Find its half-life, and the fraction of reactant left after 90 minutes.

90 minutes is three half-lives, so the fraction left is ½ × ½ × ½ = 1/8, or 12.5%. A first-order half-life doesn't depend on the starting concentration, which is how you can spot first order from data.

Try a rate law question from our Reaction Kinetics course. Answer it here and press Mark.

4. Equilibrium: an ICE table

Question: For H₂(g) + I₂(g) ⇌ 2HI(g), K_c = 64 at a certain temperature. A flask starts with 1.00 M H₂ and 1.00 M I₂. Find the equilibrium concentrations.

Let x M of H₂ react. Then I₂ also falls by x and HI rises by 2x, leaving 1.00 − x of each reactant and 2x of HI. Both sides are perfect squares, so take the square root.

So 2x = 8 − 8x, giving x = 0.800. At equilibrium [H₂] = [I₂] = 0.20 M and [HI] = 1.60 M. Check: 1.60² ÷ 0.20² = 64. A large K means products are favored, and the answer agrees.

5. Acids and bases: pH of a weak acid

Question: Find the pH of 0.10 M acetic acid, for which K_a = 1.8 × 10⁻⁵.

A weak acid ionizes only slightly, so assume 0.10 − x is still about 0.10. Then x² ÷ 0.10 = 1.8 × 10⁻⁵.

So pH = −log(1.34 × 10⁻³) = 2.87. Only 1.34% of the acid ionized, under 5%, so the assumption holds. Treating it as a strong acid would give pH 1.00, the usual trap. The pH Calculator checks both cases.

AP Chemistry scores and the 2026 score distribution

College Board reports that 75% of AP Chemistry students scored 3 or higher in 2026. Each college sets its own policy for which scores earn credit or placement.

AP Chemistry exam date 2027 and deadlines

• Exam: Thursday, May 6, 2027, in the afternoon session. In the lower 48 states, Hawaii and Washington, D.C., that starts at 12 p.m. local time.
• Ordering deadline: November 13, 2026. Your school's AP coordinator orders your exam, and your school may set an earlier date.
• Fee: $99 per exam in the US, US territories and Canada, and $129 elsewhere, for 2026-27, plus $40 for exams ordered from November 14 to March 12. College Board takes $37 off for students with significant financial need.
• Scores: released in July 2027.

Use the daily paper as a short timed practice test

1. Open today's AP Chemistry paper with a scientific calculator and a periodic table.
2. Work to the suggested time, 35 to 45 minutes, about the time of two long AP free-response questions.
3. Show units and significant figures in every calculation, and justify each claim in words where the question asks you to explain.
4. Mark it with the mark scheme and note the AP unit behind each lost mark. Alternate with the Honors Chemistry paper to cover Units 1 to 7.

Common AP Chemistry mistakes

• Skipping the mole ratio: grams of one substance never convert straight to grams of another.
• Using Celsius in gas law or rate calculations: always convert to kelvin.
• Treating a weak acid as strong: use K_a and an equilibrium expression.
• Putting solids or pure liquids into K: leave them out of the equilibrium expression.
• Explaining with "atoms want a full shell": explain with forces and energy instead, such as Coulomb's law.
• Dropping signs in electrochemistry: a positive cell potential means a negative ΔG° and a thermodynamically favorable reaction.

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