The exam at a glance
| Section | Weight | Timing | What you do |
|---|---|---|---|
| I · Multiple choice | 50% | 1 hr 30 min · 60 questions | Questions on models, experiments, particle diagrams and calculations. A scientific or graphing calculator is recommended. |
| II · Free response | 50% | 1 hr 45 min · 7 questions | 3 long questions worth 10 points each and 4 short questions worth 4 points each. Explain models, design experiments, represent data, calculate and justify claims. |
Click in Bluebook, write on paper
You answer multiple-choice questions and read the free-response questions in the Bluebook app, then handwrite free-response answers in a paper booklet.
Periodic table + equation sheet
A periodic table and a sheet of equations and constants are provided for both sections. You still need to know which equation applies and what each symbol means.
The multiple-choice section
60 questions in 90 minutes gives you 1 minute 30 seconds per question. Calculations are designed to be done quickly, often by estimating. Wrong answers lose no points.
Strategies that work
- Estimate before calculating. Answer choices are often far enough apart that rounding works.
- Draw particle diagrams for "what does the mixture look like" questions.
- Use Coulomb's law reasoning for ionization energy, lattice energy and atomic size.
- Check units and significant figures only after the chemistry is right.
- Know your strong acids and bases and the common soluble and insoluble ions.
- Flag and move on after 2 minutes. Return once the quick points are banked.
The 9 units, in plain English
Atomic Structure & Properties
Moles, electrons and periodic trends.
Be ready to: Convert moles, mass and particles; read mass and photoelectron spectra; write electron configurations; explain trends with Coulomb's law.
Compound Structure & Properties
Bonding and molecular shape.
Be ready to: Compare ionic, covalent and metallic bonding; draw Lewis structures and formal charges; use VSEPR and hybridization; predict polarity.
Properties of Substances & Mixtures
Intermolecular forces, gases and solutions.
Be ready to: Rank IMFs and boiling points; use the ideal gas law and kinetic molecular theory; calculate molarity; explain chromatography, distillation and Beer's law.
Chemical Reactions
Equations, stoichiometry and reaction types.
Be ready to: Write net ionic equations; do stoichiometry and limiting reactant problems; run titration calculations; identify acid-base and redox reactions.
Kinetics
How fast reactions happen and why.
Be ready to: Find rate laws from data; use integrated rate laws and half-life; connect mechanisms to rate laws; explain catalysts and activation energy.
Thermochemistry
Heat in reactions.
Be ready to: Use q = mcΔT and calorimetry; apply Hess's law and bond enthalpies; relate ΔH to bond breaking and forming.
Equilibrium
Reversible reactions and their balance point.
Be ready to: Write K and Q; use ICE tables; apply Le Châtelier's principle; calculate solubility with Ksp and the common-ion effect.
Acids & Bases
pH, buffers and titrations.
Be ready to: Calculate pH for strong and weak acids and bases; use Henderson-Hasselbalch for buffers; read titration curves; relate pKa to structure.
Thermodynamics & Electrochemistry
What makes reactions favorable, and batteries.
Be ready to: Predict signs of ΔS and ΔG; relate ΔG°, K and E°; describe galvanic and electrolytic cells; use Faraday's law.
Unit 3 (intermolecular forces, gases, solutions) and Unit 8 (acids and bases) are the biggest. Unit 3 ideas also explain answers across the rest of the course.
The free-response section
105 minutes for 3 long questions (10 points each) and 4 short questions (4 points each): 46 raw points in total. Long questions combine several units around one scenario.
Three 10-point questions
One scenario, many parts: calculations, particle-level explanations, experimental design and data analysis, often across several units.
Later parts may use earlier answers. If you are stuck, assume a value and keep going.
Four 4-point questions
A single focused task: one calculation, one explanation, or one representation such as a particle diagram or Lewis structure.
Short questions are quick points. Don't leave them to the end.
Calculation parts
Show the equation, substitute with units, and give an answer with appropriate significant figures.
A correct setup with an arithmetic slip can still earn most of the credit.
Explanation parts
Explain using intermolecular forces, Coulombic attraction, collisions, or comparisons of Q and K.
Compare both substances: "A has stronger IMFs than B because…".
Time plan: About 23 minutes for each long question and 9 minutes for each short one.
Habits that earn points
- Answer every lettered part, in order, with a label.
- Show the equation, the substitution and the units.
- Justify with a cause → effect sentence, not a word.
- Use the reference sheet; you don't need to memorize it.
- Blank part? Write the relationship you would use. It can earn credit.
10 traps that cost points
Bond breaking releases energy
Breaking bonds always absorbs energy. Forming bonds releases it.
IMFs vs bonds
Boiling breaks intermolecular forces, not covalent bonds within molecules.
Spectator ions in net ionic equations
Strong electrolytes in solution appear as ions; cancel spectators; keep solids, liquids, gases and weak acids whole.
Catalysts and equilibrium
A catalyst speeds up both directions equally. It does not change K or the equilibrium amounts.
Temperature and K
Only temperature changes K. Concentration and pressure changes shift the position, not K.
Weak vs strong
A dilute strong acid is still strong; a concentrated weak acid is still weak. Strength means extent of ionization.
Units in the gas law
Use kelvin, and match R to your pressure and volume units.
Rate law from the equation
Rate laws come from experiments or the slow step of a mechanism, not from the balanced equation's coefficients.
Signs of ΔG, E° and K
Favorable: ΔG° < 0, E° > 0, K > 1. Keep all three consistent.
One-sided comparisons
"A has strong IMFs" isn't enough. Compare: "A has stronger IMFs than B because…".
A study roadmap to May
A steady plan beats a last-minute rush. Shift the months to match your teacher's pacing.
- Sep – Oct
Units 1–2: foundations
Moles, electron configurations, trends, bonding and molecular shape. Master unit conversions now.
- Nov – Dec
Units 3–4: matter and reactions
IMFs, gases, solutions, net ionic equations and stoichiometry. Practice particle diagrams.
- Jan – Feb
Units 5–7: rates and energy
Kinetics, thermochemistry and equilibrium. One long free-response question each week.
- Mar – Apr
Units 8–9: acids and thermodynamics
pH, buffers, titrations, ΔG and electrochemistry. Begin full timed sections in April.
- Early May
Free-response drills
Three long and four short questions under timing. Review the traps list.
- May 2027
Exam day
Thursday, May 6, 2027 (afternoon session). Sleep well and confirm your start time with your AP coordinator.
3 practice questions
Original questions written by ACT SAT GO in the style of the exam. The free PDF has 10, with full explanations.
- Unit 8 · Weak acids
What is the pH of 0.10 M acetic acid (Ka = 1.8 × 10⁻⁵)?
- A 1.00
- B 2.87
- C 4.74
- D 5.74
Show answer
Answer: B · 2.87. [H⁺] ≈ √(Ka·C) = √(1.8 × 10⁻⁶) ≈ 1.34 × 10⁻³ M, so pH ≈ 2.87. Choice A treats it as a strong acid; C is the pKa.
- Unit 7 · Le Châtelier
For the exothermic reaction 2SO₂(g) + O₂(g) ⇌ 2SO₃(g), which change increases the equilibrium constant?
- A Lowering the temperature
- B Adding more O₂
- C Increasing the pressure
- D Adding a catalyst
Show answer
Answer: A. Only temperature changes K. For an exothermic reaction, lowering T shifts toward products and increases K. Adding O₂ or pressure shifts position only; catalysts change neither.
- Unit 9 · Thermodynamics
A reaction has ΔH° = +50 kJ/mol and ΔS° = +200 J/(mol·K). At what temperatures is it thermodynamically favorable?
- A At all temperatures
- B Only above 250 K
- C Only below 250 K
- D At no temperature
Show answer
Answer: B. ΔG = ΔH − TΔS < 0 when T > ΔH/ΔS = 50,000/200 = 250 K. Convert J to kJ consistently.
How students score
Ranges reflect recent College Board score distributions and shift a little each year. Credit and placement policies vary by college.
Aiming for a 5 in AP Chemistry?
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