OCR A GCSE Chemistry revision

Topic C1: Particles

There are 5 parts: we start with states of matter, the particle model and changes of state, and finish with electronic structure and electron configurations.

1. C1.1States of matter, the particle model and changes of state70 questions
2. C1.2Development of the model of the atom (Dalton to Bohr and Chadwick)66 questions
3. C1.3Atoms, elements and isotopesFree 58 questions
4. C1.4Relative atomic mass and isotopic abundance31 questions
5. C1.5Electronic structure and electron configurations66 questions

Topic C2: Elements, compounds and mixtures

There are 6 parts: we start with mixtures and separation techniques (filtration, crystallisation, simple and fractional distillation), and finish with nanoparticles.

1. C2.1Mixtures and separation techniques (filtration, crystallisation, simple and fractional distillation)77 questions
2. C2.2Purity, formulations and chromatographyFree 63 questions
3. C2.3Required practical: paper chromatography, Rf values and analysis of inks65 questions
4. C2.4Ionic, covalent and metallic bondingFree 21 questions
5. C2.5Structures and properties of materials25 questions
6. C2.6Nanoparticles: properties, uses and risks20 questions

Topic C3: Chemical reactions

There are 13 parts: we start with writing and balancing chemical equations, state symbols and ionic equations, and finish with the practical on electrolysis of aqueous solutions.

1. C3.1Writing and balancing chemical equations, state symbols and ionic equations43 questions
2. C3.2Conservation of mass and the moleFree 59 questions
3. C3.3Relative formula mass, percentage composition and empirical and molecular formulae47 questions
4. C3.4Limiting reactants and using moles to balance equations52 questions
5. C3.5Exothermic and endothermic reactionsFree 57 questions
6. C3.6Reaction profiles, activation energy and bond energy calculations54 questions
7. C3.7Required practical: investigating temperature changes in reacting solutions59 questions
8. C3.8Oxidation and reduction (redox) in terms of oxygen, electrons and displacement59 questions
9. C3.9Strong and weak acids, pH and hydrogen ion concentration51 questions
10. C3.10Solubility rules and precipitation reactions21 questions
11. C3.11Required practical: preparing a pure, dry sample of a soluble salt21 questions
12. C3.12Acids, bases and electrolysis37 questions
13. C3.13Required practical: electrolysis of aqueous solutions64 questions

Topic C4: Predicting and identifying reactions and products

There are 9 parts: we start with development of the periodic table and metals versus non-metals, and finish with instrumental methods and flame emission spectroscopy.

1. C4.1Development of the periodic table and metals versus non-metals71 questions
2. C4.2The periodic table and groups67 questions
3. C4.3Group 1: the alkali metals and their reactions35 questions
4. C4.4Groups 7 and 0: the halogens, displacement reactions and the noble gases60 questions
5. C4.5Transition metals: properties and uses22 questions
6. C4.6Reactivity of metals and extractionFree 25 questions
7. C4.7Identifying gases and ions65 questions
8. C4.8Required practical: identifying unknown ions (flame tests, precipitates, anion tests)24 questions
9. C4.9Instrumental methods and flame emission spectroscopy24 questions

Topic C5: Monitoring and controlling chemical reactions

There are 9 parts: we start with reacting masses, concentration and yield, and finish with reversible reactions and equilibrium.

1. C5.1Reacting masses, concentration and yield62 questions
2. C5.2Atom economy56 questions
3. C5.3Molar volume and calculations involving gases56 questions
4. C5.4Required practical: acid–alkali titration and titration calculations58 questions
5. C5.5Rates of reactionFree 63 questions
6. C5.6Calculating rates of reaction: mean rates and tangents on graphs62 questions
7. C5.7Required practical: rate of reaction by gas volume or mass loss66 questions
8. C5.8Required practical: rate of reaction by turbidity (sodium thiosulfate and hydrochloric acid)53 questions
9. C5.9Reversible reactions and equilibrium19 questions

Topic C6: Global challenges

There are 19 parts: we start with sustainable metal extraction, and finish with cells and fuel cells.

1. C6.1Sustainable metal extraction: bioleaching, phytomining and recycling metals26 questions
2. C6.2Corrosion, rusting and its prevention31 questions
3. C6.3Alloys, ceramics, composites and polymers as materials47 questions
4. C6.4The Haber process and choosing industrial conditions62 questions
5. C6.5Fertilisers and NPK compounds29 questions
6. C6.6Crude oil and hydrocarbonsFree 26 questions
7. C6.7Cracking of hydrocarbons: catalytic and steam cracking22 questions
8. C6.8Alkenes, alcohols and polymers26 questions
9. C6.9Carboxylic acids and esters34 questions
10. C6.10Condensation polymerisation (polyesters and polyamides)32 questions
11. C6.11Naturally occurring polymers: amino acids, proteins, DNA, starch and cellulose51 questions
12. C6.12Evolution of the Earth's atmosphere27 questions
13. C6.13The atmosphere and climate changeFree 23 questions
14. C6.14Carbon footprint and reducing greenhouse gas emissions68 questions
15. C6.15Atmospheric pollutants19 questions
16. C6.16Earth's resources and potable waterFree 27 questions
17. C6.17Required practical: analysis and purification of water samples65 questions
18. C6.18Life cycle assessment and recycling20 questions
19. C6.19Cells and fuel cells22 questions

Topic S: Practical and maths skills

There are 6 parts: we start with models, theories and evidence in chemistry, and finish with chemistry calculations.

1. S.1Models, theories and evidence in chemistryFree 25 questions
2. S.2Planning investigations: variables, hypotheses and risk assessment37 questions
3. S.3Practical techniques and apparatus (measuring, heating, gas collection, safety)73 questions
4. S.4Presenting data: tables, graphs, significant figures and standard form28 questions
5. S.5Uncertainty, accuracy, precision, repeatability and evaluating results36 questions
6. S.6Chemistry calculations: ratios, percentages, unit conversions and rearranging equations44 questions

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