How many papers are in OCR A-Level Chemistry B (Salters)?

Three written papers, plus a separate Practical Endorsement. Component 01 (Fundamentals of chemistry, 2h 15m, 110 marks) is 41%. Component 02 (Scientific literacy in chemistry, 2h 15m, 100 marks) is 37%. Component 03 (Practical skills in chemistry, 1h 30m, 60 marks) is 22%. Component 04 is the Practical Endorsement, Pass/Fail alongside the A-Level grade.

What are the 10 storylines?

Year 1: Elements of Life, Developing Fuels, Elements from the Sea, The Ozone Story, What's in a Medicine? Year 2: The Chemical Industry, Polymers and Life, Oceans, Developing Metals, Colour by Design. Each storyline covers specific chemistry (bonding, kinetics, equilibria, organic reactions, spectroscopy) taught through an applied context.

How does the pre-released Advance Notice article work?

OCR publishes a scientific article on their website before the Component 02 exam. It underpins one section of the paper (typically the extended-response comprehension question). Prepare with your school copy, then use a clean copy in the exam. Understanding the chemistry in the article ahead of the exam is a real advantage.

What is the Practical Endorsement?

A separate Pass/Fail reported alongside the A-Level grade. Your teacher assesses your competence across the 12 PAGs through the year (planning, apparatus use, safety, recording, analysis). It doesn't affect your A-Level letter grade, but universities often require a Pass for science courses.

Does Cognito cover OCR A-Level Chemistry B (Salters)?

Cognito has past papers and mark schemes for OCR A-Level Chemistry B (Salters) (H433). Use them for timed practice and check your answers against the official mark schemes as you go.

OCR B A-Level Chemistry B (Salters) (H433) Specification

Q: What's the difference between OCR Chemistry A and B?

OCR Chemistry A (H432) is the traditional topic-by-topic approach. OCR Chemistry B (H433, 'Salters') teaches chemistry through 10 real-world storylines (Elements of Life, Developing Fuels, Colour by Design, etc.). Both are graded the same and both cover the same underlying content. Your school picks one.

OCR A-Level Chemistry B (Salters) (H433) is a two-year linear qualification taught through 10 real-world storylines (Elements of Life, Developing Fuels, Colour by Design, and others). Students sit three written papers at the end of year 13 plus a separate Practical Endorsement (Pass/Fail), and Component 02 includes questions on a pre-released Advance Notice article.

Download the official spec (PDF)

specification overview

EL. Elements of Life
Components 01, 02
- Atomic structure and stellar nucleosynthesis
- Amounts of substance; Group 1 and 2 chemistry
- Bonding and structure
DF. Developing Fuels
Components 01, 02
- Hydrocarbons and combustion
- Alkanes, alkenes and their reactions
- Enthalpy of combustion; catalysts
ES. Elements from the Sea
Components 01, 02
- Group 17 (halogens) and redox chemistry
- Halogenoalkanes and organic reactions
- Equilibrium concepts
OZ. The Ozone Story
Components 01, 02
- Atmospheric chemistry and radical reactions
- Enthalpy, bond energies
- Rates of reaction (qualitative)
WM. What's in a Medicine?
Components 01, 02
- Alcohols, aldehydes and carboxylic acids
- Phenols and pharmaceutical chemistry
- Infrared spectroscopy and mass spectrometry
CI. The Chemical Industry (A2)
Components 01, 02
- Rate equations; equilibrium constants (Kc, Kp)
- Le Chatelier's principle applied to industrial processes
- Catalysis and industrial process design
PL. Polymers and Life (A2)
Components 01, 02
- Condensation polymers; amino acids, proteins and DNA
- Chirality and optical isomerism
- NMR spectroscopy (proton and carbon)
O. Oceans (A2)
Components 01, 02
- Acid-base equilibria; pH, buffers, indicators
- Solubility equilibria and Ksp
- Thermodynamics: enthalpy, entropy and Gibbs
DM. Developing Metals (A2)
Components 01, 02
- Transition metal chemistry
- Complex ions, ligands and colour
- Redox chemistry and electrochemistry
CD. Colour by Design (A2)
Components 01, 02
- Arenes (aromatic chemistry)
- Diazo dyes, colour and structure
- Synthetic routes and organic analysis

subject content

Paper	What's assessed	Length	Marks	Weight	Question types
Component 01 (Fundamentals of chemistry)	All storylines and practical skills	2h 15m	110	41%	Multiple-choice, structured and extended-response questions
Component 02 (Scientific literacy in chemistry)	All storylines with a pre-released Advance Notice article underpinning 20-25 marks of the paper	2h 15m	100	37%	Structured and extended-response questions, including 20-25 marks of comprehension questions on the pre-released Advance Notice article
Component 03 (Practical skills in chemistry)	Practical skills across the specification with a Practical Insert	1h 30m	60	22%	Data and practical-analysis questions using a Practical Insert

PaperComponent 01 (Fundamentals of chemistry)

What's assessedAll storylines and practical skills

Length2h 15m

Marks110

Weight41%

Question typesMultiple-choice, structured and extended-response questions

PaperComponent 02 (Scientific literacy in chemistry)

What's assessedAll storylines with a pre-released Advance Notice article underpinning 20-25 marks of the paper

Length2h 15m

Marks100

Weight37%

Question typesStructured and extended-response questions, including 20-25 marks of comprehension questions on the pre-released Advance Notice article

PaperComponent 03 (Practical skills in chemistry)

What's assessedPractical skills across the specification with a Practical Insert

Length1h 30m

Marks60

Weight22%

Question typesData and practical-analysis questions using a Practical Insert

Component 02 is underpinned by an Advance Notice article released before the exam, annotate your school copy in advance. Component 03 uses a Practical Insert with experimental data to analyse. Component 04 is the Practical Endorsement, Pass/Fail reported alongside the A-Level grade.

assessment structure

AO	What it means	Overall
AO1	Demonstrate knowledge and understanding of scientific ideas, processes, techniques and procedures.	30-35%
AO2	Apply knowledge and understanding of scientific ideas, processes, techniques and procedures in theoretical and practical contexts, including handling qualitative and quantitative data.	40-44%
AO3	Analyse, interpret and evaluate scientific information, ideas and evidence to make judgements, reach conclusions and refine practical design and procedures.	26-29%

AOAO1

What it meansDemonstrate knowledge and understanding of scientific ideas, processes, techniques and procedures.

Overall30-35%

AOAO2

What it meansApply knowledge and understanding of scientific ideas, processes, techniques and procedures in theoretical and practical contexts, including handling qualitative and quantitative data.

Overall40-44%

AOAO3

What it meansAnalyse, interpret and evaluate scientific information, ideas and evidence to make judgements, reach conclusions and refine practical design and procedures.

Overall26-29%

assessment objectives

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.

PracticalPAG1 Moles determination

What it involvesDetermine the number of moles in a solid or solution.

PracticalPAG2 Acid-base titration

What it involvesCarry out an acid-base titration to determine concentration.

PracticalPAG3 Enthalpy determination

What it involvesDetermine the enthalpy change of a reaction.

PracticalPAG4 Qualitative analysis of ions

What it involvesQualitative analysis to identify ions.

PracticalPAG5 Synthesis of an organic liquid

What it involvesPrepare and purify an organic liquid product.

PracticalPAG6 Synthesis of an organic solid

What it involvesPrepare and purify an organic solid product.

PracticalPAG7 Qualitative analysis of organic functional groups

What it involvesIdentify organic functional groups using qualitative tests.

PracticalPAG8 Electrochemical cells

What it involvesInvestigate electrochemical cells and measure electrode potentials.

PracticalPAG9 Rates of reaction (continuous monitoring)

What it involvesInvestigate a reaction rate by continuous monitoring.

PracticalPAG10 Rates of reaction (initial-rate method)

What it involvesInvestigate a reaction rate by an initial-rate method.

PracticalPAG11 pH measurement

What it involvesInvestigate pH changes during acid-base reactions.

PracticalPAG12 Research skills

What it involvesResearch skills including data analysis and scientific literature evaluation.

required practicals

Use the Advance Notice article properly
OCR publishes a pre-release article for Component 02. Annotate your school copy in advance, then use a clean copy in the exam. Understanding the article's chemistry in advance is crucial.
Learn the storylines together, apply broadly
Content is taught through 10 real-world storylines but assessed synoptically. Practise applying chemistry from one storyline (e.g. enthalpy from Developing Fuels) to unfamiliar contexts.
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.
Component 03 is data-heavy
The Practical Skills paper uses a Practical Insert with experimental data. Practise analysing unfamiliar data, evaluating methods and drawing conclusions.
Build maths fluency
AO2 is 40-44%, the largest AO. Practise moles, Kc/Kp, buffer pH, Gibbs, enthalpy, rate equations and equilibrium calculations.
Track Practical Endorsement
Assessed continuously through year. Some university science courses require a Pass, so check in with your teacher regularly.

key tips for success

Start your learning journey today...

Practise with Cognito's free past papers for this spec – or browse grade boundaries and related specifications.

A-Level Chemistry B (Salters) (OCR B)

Free past papers

A-Level Chemistry B (Salters) (OCR B) grade boundaries

Where to next

A-Level Chemistry B (Salters) (H433) Specification

Frequently asked questions

Past papers for this spec, free