OCR A-Level Chemistry
Explore your course, one topic at a time.
Course overview
The OCR A-Level Chemistry specification covers 45 topics with 1906 learning objectives (H432). Use the topic browser below to explore subtopics, exam tips, common mistakes, and key terminology for each area of the course.
- 45 topics
- 1 study page
- 1906 learning objectives
- 629
- teaching notes
- 45
- topics
- 1
- audio lessons
Your exams
- Periodic table, elements and physical chemistryFriday, 28 May 2027, AM
- Synthesis and analytical techniquesThursday, 10 June 2027, AM
- Unified chemistryThursday, 17 June 2027, AM
Always confirm dates and times with your exam centre.
| Paper | Time | Marks | Weight |
|---|---|---|---|
| Periodic table, elements and physical chemistry | 135 min | 100 | 37% |
| Synthesis and analytical techniques | 135 min | 100 | 37% |
| Unified chemistry | 90 min | 70 | 26% |
Explore your topics
45 topics
Development of practical skills in chemistry4 topics
- Planning3 specification points covering (a) experimental design, including to solve problems set in a practical context, (b) identification of variables that must…9 objectives
- Implementing3 specification points covering (a) how to use a wide range of practical apparatus and techniques correctly, (b) appropriate units for measurements, (c)…9 objectives
- Analysis6 specification points covering (a) processing, analysing and interpreting qualitative and quantitative experimental results, (b) use of appropriate…18 objectives
- Evaluation5 specification points covering (a) how to evaluate results and draw conclusions, (b) the identification of anomalies in experimental measurements, (c) the…15 objectives
Practical Endorsement in chemistry2 topics
- Practical skills14 specification points covering Independent thinking, (a) apply investigative approaches and methods to practical work, Use and application of scientific…42 objectives
- Use of apparatus and techniques20 specification points covering (a) use of appropriate apparatus to record a range of measurements (to include mass, time, volume of liquids and gases,…62 objectives
Foundations in chemistry7 topics
- Atomic structure and isotopes9 specification points covering (a) isotopes as atoms of the same element with different numbers of neutrons and different masses, (b) atomic structure in…27 objectives · 1 study page
- Compounds, formulae and equations5 specification points covering Formulae and equations, (a) the writing of formulae of ionic compounds from ionic charges, including:, (i) prediction of…15 objectives
- Amount of substance26 specification points covering The mole, (a) explanation and use of the terms:, (i) amount of substance and related ideas.79 objectives
- Acids9 specification points covering Acids, bases, alkalis and neutralisation, (a) the formulae of the common acids (HCl, H₂SO₄, HNO₃ and CH₃COOH) and the common…29 objectives
- Redox10 specification points covering Oxidation number, (a) rules for assigning and calculating oxidation number for atoms in elements, compounds and ions, (b)…30 objectives
- Electron structure12 specification points covering Energy levels, shells, sub-shells, atomic orbitals, electron configuration, (a) the number of electrons that can fill the…36 objectives
- Bonding and structure27 specification points covering Ionic bonding, (a) ionic bonding as electrostatic attraction between positive and negative ions, and the construction of…81 objectives
Periodic table and energy7 topics
- Periodicity18 specification points covering The structure of the periodic table, (a) the periodic table as the arrangement of elements:, (i) by increasing atomic…58 objectives
- Group 212 specification points covering Redox reactions and reactivity of Group 2 metals, (a) the outer shell s² electron configuration and the loss of these…36 objectives
- The halogens13 specification points covering Characteristic physical properties, (a) existence of halogens as diatomic molecules and explanation of the trend in the…39 objectives
Qualitative analysis
The periodic table - 3.1.4 Qualitative analysis7 specification points covering Tests for ions, (a) qualitative analysis of ions on a test-tube scale; processes and techniques needed to identify the…21 objectives- Enthalpy changes21 specification points covering Enthalpy changes: ∆H of reaction, formation, combustion and neutralisation, (a) explanation that some chemical reactions…63 objectives
- Reaction rates15 specification points covering Simple collision theory, (a) the effect of concentration, including the pressure of gases, on the rate of a reaction, in…46 objectives
- Chemical equilibrium9 specification points covering Dynamic equilibrium and le Chatelier’s principle, (a) explanation that a dynamic equilibrium exists in a closed system when…27 objectives
Core organic chemistry7 topics
- Basic concepts of organic chemistry26 specification points covering Naming and representing the formulae of organic compounds, (a) application of IUPAC rules of nomenclature for…78 objectives
- Alkanes9 specification points covering Properties of alkanes, (a) alkanes as saturated hydrocarbons containing single C–C and C–H bonds as σ-bonds (overlap of…27 objectives
- Alkenes30 specification points covering Properties of alkenes, (a) alkenes as unsaturated hydrocarbons containing a C=C bond comprising a π-bond (sideways overlap…90 objectives
- Alcohols11 specification points covering Properties of alcohols, (a) (i) the polarity of alcohols and an explanation, in terms of hydrogen bonding, of the water…35 objectives
- Haloalkanes11 specification points covering Substitution reactions of haloalkanes, (a) hydrolysis of haloalkanes in a substitution reaction:, (i) by aqueous alkali and…33 objectives
Organic synthesis
Alcohols, haloalkanes and analysis - 4.2.3 Organic synthesis12 specification points covering Practical skills, (a) the techniques and procedures for:, (i) use of Quickfit apparatus including for distillation and…36 objectives- Analytical techniques17 specification points covering Infrared spectroscopy, (a) infrared (IR) radiation causes covalent bonds to vibrate more and absorb energy, (b) absorption…51 objectives
Physical chemistry and transition elements8 topics
- How fast?25 specification points covering Orders, rate equations and rate constants, (a) explanation and use of the terms: rate of reaction, order, overall order,…75 objectives
- How far?10 specification points covering Equilibrium, (a) use of the terms mole fraction and partial pressure, (b) calculation of quantities present at equilibrium,…31 objectives
- Acids, bases and buffers29 specification points covering Brønsted–Lowry acids and bases, (a) (i) a Brønsted–Lowry acid as a species that donates a proton and a Brønsted–Lowry base…88 objectives
- Lattice enthalpy12 specification points covering (a) explanation of the term lattice enthalpy (formation of 1 mol of ionic lattice from gaseous ions, ∆LEH) and use as a…36 objectives
- Enthalpy and entropy10 specification points covering Entropy, (a) explanation that entropy is a measure of the dispersal of energy in a system which is greater, the more…30 objectives
- Redox and electrode potentials19 specification points covering Redox, (a) explanation and use of the terms oxidising agent and reducing agent (see also 2.1.5 Redox), (b) construction of…57 objectives
- Transition elements31 specification points covering Properties, (a) the electron configuration of atoms and ions of the d-block elements of Period 4 (Sc–Zn), given the atomic…93 objectives
Qualitative analysis
Transition elements - 5.3.2 Qualitative analysis4 specification points covering Tests for ions, (a) qualitative analysis of ions on a test-tube scale: processes and techniques needed to identify the…12 objectives
Organic chemistry and analysis10 topics
- Aromatic compounds20 specification points covering Benzene and aromatic compounds, (a) the comparison of the Kekulé model of benzene with the subsequent delocalised models…60 objectives
- Carbonyl compounds13 specification points covering Reactions of carbonyl compounds, (a) oxidation of aldehydes using Cr₂O₇²⁻/H⁺ (i.e.42 objectives
- Carboxylic acids and esters13 specification points covering Properties of carboxylic acids, (a) explanation of the water solubility of carboxylic acids in terms of hydrogen bonding,…39 objectives
- Amines5 specification points covering Basicity and preparation of amines, (a) the basicity of amines in terms of proton acceptance by the nitrogen lone pair and…15 objectives
- Amino acids, amides and chirality9 specification points covering Reactions of amino acids, (a) the general formula for an α-amino acid as RCH(NH₂)COOH and the following reactions of amino…29 objectives
- Polyesters and polyamides11 specification points covering Condensation polymers, (a) condensation polymerisation to form:, (i) polyesters and related ideas.33 objectives
- Carbon–carbon bond formation9 specification points covering Extending carbon chain length, (a) the use of C–C bond formation in synthesis to increase the length of a carbon chain (see…27 objectives
Organic synthesis
Nitrogen compounds, polymers and synthesis - 6.2.5 Organic synthesis14 specification points covering Practical skills, (a) the techniques and procedures used for the preparation and purification of organic solids involving…42 objectives- Chromatography and qualitative analysis14 specification points covering Types of chromatography, (a) interpretation of one-way TLC chromatograms in terms of Rf values, (b) interpretation of gas…42 objectives
- Spectroscopy21 specification points covering NMR Spectroscopy, (a) analysis of a carbon-13 NMR spectrum of an organic molecule to make predictions about:, (i) the…63 objectives
About this course
About OCR A-Level Chemistry
OCR A-Level Chemistry A (H432) is a linear qualification that delves deeply into the principles of chemistry, equipping students with a robust understanding of both the theoretical and practical aspects of the subject. The course is structured around six modules, starting with foundational concepts in atomic structure, bonding, and calculations, then progressing through inorganic, physical, and organic chemistry. A distinctive feature of OCR Chemistry is its emphasis on contextual and synoptic learning, where students are encouraged to draw connections between different topic areas, particularly in the unified chemistry paper.
Throughout the two-year course, students develop essential scientific skills such as experimental design, data analysis, and mathematical reasoning, with at least 20% of the marks in written exams attributed to mathematical competency. The specification also places a strong focus on practical work, with a separate Practical Endorsement reported alongside the A-Level grade. This hands-on approach ensures that learners can not only recall chemical facts but also apply their knowledge in laboratory settings and unseen scenarios.
The qualification is divided into six teaching modules: Development of practical skills, Foundations in chemistry, Periodic table and energy, Core organic chemistry, Physical chemistry and transition elements, and Organic chemistry and analysis. This logical progression builds on GCSE knowledge and prepares students for further study in chemistry, medicine, engineering, and other science-related fields. With a rigorous assessment structure and clear mark schemes, it is well-regarded by universities and employers alike.
Assessment Structure
The OCR A-Level Chemistry A qualification is assessed through three written examinations at the end of the two-year course. Paper 1 (Periodic table, elements and physical chemistry) is worth 100 marks and accounts for 37% of the total A-Level, with a duration of 2 hours 15 minutes. Paper 2 (Synthesis and analytical techniques) also carries 100 marks and 37% weighting, lasting 2 hours 15 minutes. Paper 3 (Unified chemistry) is a 70-mark paper contributing 26% of the final grade, taken over 1 hour 30 minutes. In addition, students must complete a series of core practical activities throughout the course to achieve a Practical Endorsement, which is reported separately as a Pass/Fail and does not contribute to the A-Level grade. The total qualification mark is 270.
Why Choose OCR?
- OCR A-Level Chemistry A is known for its clear and logical structure, splitting content into manageable modules that build progressively. This makes planning and revision more straightforward compared to some non-linear specifications. The unified chemistry paper also promotes deep, synoptic understanding, rewarding students who can think across the whole specification.
- The specification has a strong emphasis on practical science, but without the pressure of coursework contributing to the final grade. The Practical Endorsement is separately reported, so students can focus on mastering experimental skills in lessons without high-stakes assessment conditions. This often appeals to schools and colleges that want to ensure genuine practical proficiency.
- OCR provides a wealth of high-quality support materials, including past papers, examiner reports, and endorsed textbooks. Their mark schemes are detailed and consistent, helping teachers to deliver effective feedback and students to understand exactly what examiners are looking for. The exam board also offers flexibility in the optional topics (e.g., in Module 5) allowing some tailoring to student interests.
Frequently Asked Questions
What is the difference between OCR A and OCR B (Salters) Chemistry?
OCR offers two distinct A-Level Chemistry specifications: Chemistry A (H432) and Chemistry B (Salters, H433). Chemistry A follows a more traditional, content-led approach organised by fundamental topics such as atoms, bonding, and organic families. In contrast, Chemistry B (Salters) uses a context-based approach, introducing chemical concepts through real-world storylines and applications, such as the chemistry of the atmosphere or pharmaceuticals. While the depth and rigour are comparable, students often find Chemistry A more straightforward to revise due to its linear topic structure, whereas Salters suits those who prefer learning through narrative and practical contexts.
How are practical skills assessed in OCR A-Level Chemistry?
Practical skills are assessed in two ways for OCR A-Level Chemistry A. First, at least 15% of the marks in the written exams test understanding of practical procedures, data analysis, and evaluation of experimental methods. Second, students must complete a minimum of 12 core practical activities over the two years to obtain the Practical Endorsement. This endorsement is assessed internally by teachers against set criteria and is reported separately as a Pass or Fail on the certificate. It does not contribute to the A-Level grade, but achieving a Pass is often essential for progression to many university science courses.
Is OCR A-Level Chemistry harder than AQA?
Both OCR and AQA A-Level Chemistry cover similar content and are equally rigorous, but there are some differences in style and assessment. OCR papers tend to feature more structured questions with clear scaffolding, which some students find more approachable, while AQA often includes longer, open-response questions that require strong written communication. The difficulty is subjective and depends on a student’s strengths; for example, OCR’s emphasis on synoptic thinking in the Unified Chemistry paper may suit those who enjoy linking topics, whereas AQA’s required practical questions are integrated into all papers. Grade boundaries also vary year-on-year, but both boards are well-respected by universities.
What resources are available for OCR A-Level Chemistry revision?
There is a wide range of official and third-party resources for OCR A-Level Chemistry A. OCR’s website provides past papers, mark schemes, and examiner reports, which are essential for exam practice. Textbooks endorsed by OCR, such as those published by Oxford University Press or CGP, align closely with the specification. Additionally, online platforms like MasteryMind offer tailored revision notes, quizzes, and video explanations organised exactly by module. Many students also benefit from YouTube channels like ‘MaChemGuy’ and ‘Allery Chemistry’ that deliver clear OCR-focused tutorials, as well as flashcards on Quizlet for memorising key definitions and mechanisms.
Do I need the Practical Endorsement for university entry?
For most university courses in chemistry, biochemistry, medicine, dentistry, and related fields, achieving a Pass in the Practical Endorsement is a standard entry requirement, even though it does not affect the A-Level grade. Universities use the endorsement to confirm that students have gained hands-on laboratory skills and can work safely and competently. If a student does not achieve the endorsement, they may still be considered, but it could limit options or require a proven equivalent experience. It is therefore strongly advised to engage fully with the core practical activities and maintain a lab book throughout the course to secure this vital component.
Assessment and exam guidance
Assessment Objectives
AO1
31%-34%Demonstrate knowledge and understanding of scientific ideas, processes, techniques and procedures.
AO2
40%-44%Apply knowledge and understanding of scientific ideas, processes, techniques and procedures in a theoretical context, in a practical context, when handling qualitative data and when handling quantitative data.
AO3
25%-28%Analyse, interpret and evaluate scientific information, ideas and evidence, including in relation to issues, to make judgements and reach conclusions and to develop and refine practical design and procedures.
Exam Structure
OCR A-Level (H432)
Periodic table, elements and physical chemistry
2h 15m
Duration
100
Marks
37%
Weighting
Synthesis and analytical techniques
2h 15m
Duration
100
Marks
37%
Weighting
Unified chemistry
1h 30m
Duration
70
Marks
26%
Weighting
Tips and common mistakes
Common Exam Mistakes
Pitfalls to avoid in your exams
- •Lists apparatus without linking it to the quantities or precision needed; justify each choice against the measurement.
- •Omits controlled variables; name each one and state how it is kept constant.
- •Describes a single reading with no repeats; include repeats and explain how they improve reliability.
- •Ignores safety; identify the specific hazards of the chosen chemicals and give control measures.
- •Confuses the controlled variable with the independent variable; the independent variable is changed deliberately, the controlled variable is held constant.
- •Names a factor that cannot affect the result; choose only factors that could genuinely influence the measurement.
- •Suggests controlling every conceivable factor; control only those that could realistically affect the outcome.
- •Gives a control without a method; state how the variable is kept constant, for example by using a water bath.
Top Examiner Tips
Expert advice for exam success
- •Read the practical context carefully and tailor the method to the named chemicals and equipment.
- •Structure the answer as aim, variables, apparatus, procedure, data handling and safety so nothing is missed.
- •Justify choices, for example why a burette suits accurate volume measurement, rather than listing equipment.
- •State how repeats and controlled variables improve the reliability and fairness of the results.
- •Ask which factors could change the dependent variable, then decide which are being varied and which must be fixed.
- •Check that each suggested control includes a practical method of keeping it constant.
- •Remember that 'where appropriate' means controlling only realistic confounding factors.
- •Acknowledge factors that cannot be controlled as limitations rather than ignoring them.
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