specification overview
OCR A-Level Chemistry A (H432) is a two-year linear qualification structured around six modules, from foundations in chemistry through to organic chemistry and analysis. Students sit three written papers at the end of year 13, plus a separate Practical Endorsement (Pass/Fail) covering 12 practical activity groups (PAGs). All papers are synoptic.
subject content
1. Development of practical skills in chemistry
All papers- Practical skills assessed in written examinations
- Practical skills assessed in the Practical Endorsement
2. Foundations in chemistry
Components 01, 02- Atoms, compounds, molecules and equations
- Amount of substance; acid-base and redox reactions
- Electrons, bonding and structure
3. Periodic table and energy
Component 01- The Periodic Table and periodicity; Group 2 and Group 17
- Qualitative analysis
- Enthalpy changes; reaction rates and equilibrium (qualitative)
4. Core organic chemistry
Component 02- Basic concepts of organic chemistry; hydrocarbons
- Alcohols and haloalkanes
- Organic synthesis; analytical techniques (infrared and mass spectrometry)
5. Physical chemistry and transition elements
Component 01- Reaction rates and equilibrium (quantitative)
- pH and buffers
- Enthalpy, entropy and free energy
- Redox and electrode potentials
- Transition elements
6. Organic chemistry and analysis
Component 02- Aromatic compounds; carbonyl compounds; carboxylic acids and esters
- Nitrogen compounds, polymers and synthesis
- Chromatography and spectroscopy (NMR)
assessment structure
| Paper | What's assessed | Length | Marks | Weight | Question types |
|---|---|---|---|---|---|
| Component 01 (Periodic table, elements and physical chemistry) | Modules 1, 2, 3 and 5 | 2h 15m | 100 | 37% | Multiple-choice (~15 marks), structured and extended-response questions |
| Component 02 (Synthesis and analytical techniques) | Modules 1, 2, 4 and 6 | 2h 15m | 100 | 37% | Multiple-choice (~15 marks), structured and extended-response questions |
| Component 03 (Unified chemistry) | All six modules | 1h 30m | 70 | 26% | Synoptic questions drawing content from across the whole specification |
All three components include synoptic assessment. Component 04 is the Practical Endorsement, a non-exam assessment reported separately (Pass/Fail) alongside the A-Level grade.
assessment objectives
| AO | What it means | Overall |
|---|---|---|
| AO1 | Demonstrate knowledge and understanding of scientific ideas, processes, techniques and procedures. | 31-34% |
| AO2 | Apply knowledge and understanding of scientific ideas, processes, techniques and procedures in theoretical and practical contexts, including when handling qualitative and quantitative data. | 40-43% |
| AO3 | Analyse, interpret and evaluate scientific information, ideas and evidence to make judgements, reach conclusions and refine practical design and procedures. | 25-28% |
required practicals
| Practical | What it involves |
|---|---|
| PAG1 Moles determination | Determine the number of moles in a solid or solution. |
| PAG2 Acid-base titration | Carry out an acid-base titration to determine concentration. |
| PAG3 Enthalpy determination | Determine the enthalpy change of a reaction. |
| PAG4 Qualitative analysis of ions | Qualitative analysis to identify ions. |
| PAG5 Synthesis of an organic liquid | Prepare and purify an organic liquid product. |
| PAG6 Synthesis of an organic solid | Prepare and purify an organic solid product. |
| PAG7 Qualitative analysis of organic functional groups | Identify organic functional groups using qualitative tests. |
| PAG8 Electrochemical cells | Investigate electrochemical cells and measure electrode potentials. |
| PAG9 Rates of reaction (continuous monitoring) | Investigate a reaction rate by continuous monitoring. |
| PAG10 Rates of reaction (initial-rate method) | Investigate a reaction rate by an initial-rate method. |
| PAG11 pH measurement | Investigate pH changes during acid-base reactions. |
| PAG12 Research skills | Research skills including data analysis and scientific literature evaluation. |
key tips for success
Learn the module → component mapping
Component 01 covers Modules 1, 2, 3 and 5 (physical + inorganic focus). Component 02 covers Modules 1, 2, 4 and 6 (organic + analytical focus). Component 03 covers everything synoptically.
Take Component 03 seriously
The Unified Chemistry paper is 26% and synoptic across all six modules. Practise linking Components 01 and 02 material rather than treating them as separate revision blocks.
Master the 12 PAGs
Practical Activity Groups feed both written-paper questions (all three papers) and the Practical Endorsement. Learn method, apparatus, expected observations for each.
Practise multiple-choice sections
Components 01 and 02 each include ~15 marks of MC questions. Practise them separately so you're not caught by the format.
Interpret NMR and IR spectra
Spectroscopy is worth marks across Components 02 and 03. Practise assigning peaks in proton and carbon NMR, plus combined-spectra questions.
Track Practical Endorsement
Assessed continuously through year. Some university science courses require a Pass, so check in with your teacher regularly.
Where to next
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