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Chem · Progress Checks

AP Chemistry Progress Check walkthroughs.

Unit-by-unit explanations of the MCQ and FRQ content on AP Classroom Progress Checks. Each unit page shows the topics tested, the most common student mistakes, and a tip from someone who scored a 5.

Updated July 2025 Written by Mahmudul Hasan Free · No signup
9 units

All units, expandable.

Click a unit to see MCQ topics, FRQ structure, common mistakes, and a tip from a student who scored a 5.

U01Atomic Structure and Properties22 questions covered · MCQ + FRQ walkthroughs
MCQ guidance
  • Mass spec
  • Electron config
  • Periodic trends
FRQ guidance
  • PES graph analysis
Common mistake
Reading PES peaks left-to-right (should be right-to-left for energy).
Tip from a 5-scorer
Energy increases left, electron count is peak height.
U02Compound Structure and Properties24 questions covered · MCQ + FRQ walkthroughs
MCQ guidance
  • Ionic vs. covalent
  • Bond polarity
  • Intermolecular forces
FRQ guidance
  • IMF ranking justifications
Common mistake
Listing IMFs without ranking them.
Tip from a 5-scorer
Always rank: ion-dipole > H-bond > dipole-dipole > LDF.
U03Properties of Substances and Mixtures24 questions covered · MCQ + FRQ walkthroughs
MCQ guidance
  • Gas laws
  • Solutions
  • Particulate diagrams
FRQ guidance
  • Stoichiometry of mixtures
Common mistake
Forgetting to convert moles to particles for diagrams.
Tip from a 5-scorer
Particulate diagrams are mole ratios in disguise.
U04Chemical Reactions26 questions covered · MCQ + FRQ walkthroughs
MCQ guidance
  • Stoichiometry
  • Net ionic
  • Titration
FRQ guidance
  • Titration curve analysis
Common mistake
Writing molecular equations when net ionic is required.
Tip from a 5-scorer
Always strip spectator ions on FRQs unless asked otherwise.
U05Kinetics26 questions covered · MCQ + FRQ walkthroughs
MCQ guidance
  • Rate laws
  • Integrated rate
  • Mechanisms
FRQ guidance
  • Rate law from experimental data
Common mistake
Choosing rate law from coefficients (use the data, not the equation).
Tip from a 5-scorer
Compare runs with one variable changed at a time.
U06Thermochemistry24 questions covered · MCQ + FRQ walkthroughs
MCQ guidance
  • Calorimetry
  • Enthalpy
  • Hess’s Law
FRQ guidance
  • Enthalpy diagrams
Common mistake
Forgetting sign conventions on q.
Tip from a 5-scorer
Heat absorbed by system = +; released = −. Tag every q.
U07Equilibrium28 questions covered · MCQ + FRQ walkthroughs
MCQ guidance
  • Le Châtelier
  • K expressions
  • ICE tables
FRQ guidance
  • Pressure/temperature shift problems
Common mistake
Treating temperature changes like pressure changes in Le Ch.
Tip from a 5-scorer
Temperature SHIFTS K. Pressure doesn’t.
U08Acids and Bases26 questions covered · MCQ + FRQ walkthroughs
MCQ guidance
  • pH/pOH
  • Buffers
  • Titrations
FRQ guidance
  • Buffer pH after mixing
Common mistake
Forgetting the Henderson-Hasselbalch when conditions allow.
Tip from a 5-scorer
HH applies near pKa with both species present.
U09Applications of Thermodynamics22 questions covered · MCQ + FRQ walkthroughs
MCQ guidance
  • Entropy
  • Gibbs free energy
  • Electrochemistry
FRQ guidance
  • ΔG calculations
Common mistake
Sign confusion on ΔG = ΔH − TΔS.
Tip from a 5-scorer
Spontaneous: ΔG < 0. Memorize the 4 sign combinations.
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Practice loop
Do a Progress Check. Score yourself. Adjust.

After each unit, plug your AP Classroom score breakdown into the calculator. You’ll see your trajectory in real numbers, not vibes.

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Frequently asked questions

Quick answers — written by humans, not a chatbot.

What's the difference between Chem Progress Checks and the real AP exam?

Progress Checks are unscaled — they’re unit-by-unit MCQ + FRQ practice that AP Classroom assigns. The real AP exam uses a curve to map your raw composite to a 1–5. The walkthroughs above explain the reasoning; the calculator estimates your exam score.

Should I do every Progress Check or skip around?

Do them in order the first time — each one builds on the last. If you’re reviewing in May, target the units where you’re weakest using the unit summaries above.

Why don't you publish exact answer keys?

AP Classroom assignments are graded as your own work. Posting raw keys would help cheaters and harm the students using Curve for actual studying. Our walkthroughs explain reasoning, not letter answers.

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