specification overview
OCR Twenty First Century GCSE Chemistry B (J258) is a separate-science qualification developed with the University of York, teaching chemistry through real-world contexts and stories. Tiered (Foundation grades 5-1 or Higher grades 9-4), linear, and graded 9-1. Two papers per candidate: 'Breadth in chemistry' and 'Depth in chemistry'; both papers assess content from all eight teaching chapters.
subject content
C1. Air and water
Both papers- Atmospheric chemistry and greenhouse gases
- Water quality and purification
C2. Chemical patterns
Both papers- Atomic structure and periodic table
- Groups 1, 7, 0 and transition metals
C3. Chemicals of the natural environment
Both papers- Ionic and covalent bonding, structures
- Chemical reactions of common natural substances
C4. Material choices
Both papers- Polymers, alloys and composites
- Life-cycle assessments and sustainability
C5. Chemical analysis
Both papers- Testing for chemical species
- Chromatography, chemical formulae and yields
C6. Making useful chemicals
Both papers- Rates of reaction and equilibria
- Industrial chemistry (Haber process, extraction)
C7. Ideas about Science
Both papers- Investigating phenomena; conclusions from data
- Developing scientific explanations; science and society
C8. Practical skills
Both papers- Apparatus and techniques across the 8 PAGs
- At least 15% of marks assess practical skills
assessment structure
| Paper | What's assessed | Length | Marks | Weight | Question types |
|---|---|---|---|---|---|
| Breadth in chemistry (J258/01, Foundation) | All eight chapters (C1-C8) | 1h 45m | 90 | 50% | Short-answer: structured, calculations, practical-skills questions. |
| Depth in chemistry (J258/02, Foundation) | All eight chapters (C1-C8), with greater depth and synoptic linking | 1h 45m | 90 | 50% | Structured, calculations, practical-skills questions, plus extended-response (6-mark, level-of-response) questions. |
| Breadth in chemistry (J258/03, Higher) | All eight chapters (C1-C8) | 1h 45m | 90 | 50% | Short-answer: structured, calculations, practical-skills questions. |
| Depth in chemistry (J258/04, Higher) | All eight chapters (C1-C8), with greater depth and synoptic linking | 1h 45m | 90 | 50% | Structured, calculations, practical-skills questions, plus extended-response (6-mark, level-of-response) questions. |
Foundation candidates sit J258/01 + J258/02; Higher candidates sit J258/03 + J258/04. Both papers assess content from all eight chapters at the entered tier - the split is by question style (Breadth = short-answer only; Depth = adds extended-response 6-markers), not by topic. Both papers include the Ideas about Science strand and practical skills questions.
assessment objectives
| AO | What it means | Overall |
|---|---|---|
| AO1 | Demonstrate knowledge and understanding of scientific ideas, techniques and procedures. | 40% |
| AO2 | Apply knowledge and understanding of scientific ideas, techniques and procedures. | 40% |
| AO3 | Analyse information and ideas to interpret and evaluate, make judgements and draw conclusions. | 20% |
required practicals
| Practical | What it involves | Topic |
|---|---|---|
| PAG 1 Reactivity trend | – | C8 |
| PAG 2 Electrolysis | – | C8 |
| PAG 3 Separation techniques | – | C8 |
| PAG 4 Distillation | – | C8 |
| PAG 5 Identification of species | – | C8 |
| PAG 6 Titration | – | C8 |
| PAG 7 Production of salts | – | C8 |
| PAG 8 Measuring rates of reaction | – | C8 |
higher vs foundation
| Aspect | Foundation tier | Higher tier |
|---|---|---|
| Grades available | Grades 5 to 1 | Grades 9 to 4, plus an allowed grade 3 |
| Papers | J258/01 (Breadth) and J258/02 (Depth) | J258/03 (Breadth) and J258/04 (Depth) |
| Content scope | Foundation content only | Foundation + Higher-only content (statements in bold in the spec) |
key tips for success
Learn the context-based approach
OCR B frames chemistry through real-world contexts (climate change, water quality, materials choice). Practise applying chemistry to novel contexts.
Master 'Ideas about Science'
Both papers include the Ideas about Science strand (evidence, risk, developing scientific explanations, correlation vs causation). Learn each and apply.
Learn PAGs
Practical Activity Groups are assessed through written questions. Learn method, apparatus and expected results for each.
Build a case-study bank
OCR B rewards real-world examples. Follow chemistry news (recent research, industrial developments, environmental issues) and build a bank.
Master moles for Higher tier
Higher-tier moles calculations recur. Practise mass, concentration, gas volume and reacting mass calculations.
Use past papers
OCR B has fewer past papers than OCR A or AQA, use every available paper plus specimen materials.
Where to next
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