Chemistry Zen: Exam Practice

Chemistry Zen turns chemistry into focused, repeatable practice. Balance a reaction, work through a mole or concentration problem, check your answer, and open the theory or the worked solution exactly when you need it.

14 TOPICS, 78 SUBTOPICS

- Atoms and moles: particles, masses, electron configurations, the periodic table, nuclear decay, electromagnetic spectrum
- Bonding and structure: bonds, Lewis structures, molecular shape, polarity
- States and solutions: concentration, dilution, gases, intermolecular forces
- Chemical reactions: balancing, reacting moles, limiting reactant, yield
- Energy changes: calorimetry, Hess's law, bond enthalpy, entropy, Gibbs energy
- Reaction rates: rate data, rate laws, Arrhenius, catalysts
- Equilibrium: K and Q, Le Chatelier, equilibrium concentrations, Ksp
- Acids and bases: pH, neutralisation, weak acids, buffers, titration curves
- Redox and cells: oxidation states, cell potential, electrolysis, Nernst
- Organic chemistry: functional groups, isomers, products, polymers, spectroscopy
- Molecules of life: sugars, fats, amino acids, peptides and protein structure
- Enzymes, energy and DNA: enzymes, ATP, nucleotides, base pairing, from DNA to protein
- Lab methods: apparatus, separation, measurement error, titration, chromatography
- Scientific reasoning: particle diagrams, experiment design, data trends

EXAM PREP

Ten exam routes, each built from the topics its course covers:

- AP Chemistry
- AQA A-level Chemistry (7405)
- IB Chemistry SL and IB Chemistry HL
- Chemie-Abitur NRW 2027, Grundkurs and Leistungskurs
- Bac: Chemistry, the chemistry part of the French spécialité physique-chimie (no physics or practical exam)
- NY Regents Physical Science: Chemistry (June 2027)
- Japan's Common Test (共通テスト): 化学基礎 and 化学 (January 2027)

Every question is original practice, not an official exam paper. Chemistry Zen is not affiliated with College Board, AQA, the International Baccalaureate, the NRW and French Ministries of Education, the New York State Education Department (NYSED) or Japan's National Center for University Entrance Examinations.

BUILT FOR PRACTICE

- Coefficient input: balance equations by setting each coefficient, just as you would on paper.
- Many question types: numerical, multiple choice and multi-part.
- Difficulty that follows you: every subtopic has several levels, from foundations to multi-step problems.
- Periodic table at hand during topic practice, coloured by element family. Tap an element for its name, atomic number and atomic mass.
- Theory beside the problem: theory cards for every subtopic, most with a worked example and a common mistake, plus hints and worked solutions.
- Mistake journal: missed questions are saved for another try.
- Three modes: a relaxed zen session, a timed session, or one that ends after a set number of errors.
- Statistics: accuracy and progress for every topic.
- Ranking: compare your correct answers with other learners. It is optional: Sign in with Google to join. Practice works fully without an account.

No ads, no analytics. Practice works offline. English, Spanish, French, German, Japanese and Russian, light and dark themes.

HOW IT WORKS

1. Choose a topic, a subtopic or an exam route.
2. Solve a problem at your current level.
3. Check your answer and read the worked solution.
4. Level up and return to your mistakes.

The first topic, Atoms and moles, is free end to end, and every other topic is free except its last subtopic. Premium unlocks those subtopics, all exam routes and detailed statistics. Subscription and lifetime options are shown in the app with local pricing before purchase.

Subscriptions renew automatically unless cancelled at least 24 hours before the end of the current period. Manage or cancel them in your Google Play account settings.

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