OCR A-Level Chemistry A Active Recall Guide (H432)
OCR · A-Level
OCR A-Level Chemistry A Active Recall Guide
Every section of specification H432 written as exam-style questions with the answers printed after them. 1,913 questions across 17 sections and 160 subtopics, covering all six modules including the practical activity groups and the mathematics examined on the papers.
- OCR
- A-Level
- Specification H432
- 1,913 questions
Guide overview All 17 sections Sample questions Papers and weighting Look inside Questions and answers
What the exam asks of you
OCR A-Level Chemistry A is assessed by three written papers at the end of Year 13. Periodic Table, Elements and Physical Chemistry and Synthesis and Analytical Techniques are 2 hours 15 minutes and 100 marks each, worth 37 per cent apiece. Unified Chemistry is 1 hour 30 minutes and 70 marks, worth 26 per cent, and can draw on any part of the specification at once.
Chemistry at this level is a large number of precise things that cannot be worked out in the hall: a reagent, a set of conditions, a mechanism, a definition, a calculation route. Recall is the limiting factor on almost every mark, and a list of questions is the instrument that matches it.
| Paper | Covers | Length | Marks | Weighting |
|---|---|---|---|---|
|
Component 01 Periodic Table, Elements and Physical Chemistry |
Modules 1, 2, 3 and 5: the foundations, the periodic table and energy, and physical chemistry and transition elements Multiple-choice, structured and extended-response questions Includes questions on the practical activity groups and on mathematics at Level 2 or above |
2 hours 15 minutes | 100 marks | 37% |
|
Component 02 Synthesis and Analytical Techniques |
Modules 1, 2, 4 and 6: the foundations, core and advanced organic chemistry, and the analytical techniques Multiple-choice, structured and extended-response questions Includes questions on the practical activity groups and on mathematics at Level 2 or above |
2 hours 15 minutes | 100 marks | 37% |
|
Component 03 Unified Chemistry |
Any content from the specification, drawn together synoptically Questions on experimental method, on planning and on the analysis of data Includes extended-response questions set in unfamiliar contexts |
1 hour 30 minutes | 70 marks | 26% |
|
Component 04 Practical Endorsement in Chemistry |
Reported separately from the A-Level grade as a pass or not classified Assessed by the teacher across the twelve practical activity groups |
Assessed throughout the course | No marks | Reported separately |
What is in the guide
All 17 sections
Every section has its own page with its subtopics, what it covers and sample questions.
Sample questions
Taken from the guide. Answer each one closed book first, then open the answer.
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Atomic structure, isotopes and counting sub-atomic particles
Define the mass number of an atom.
Show the answer
The total number of protons and neutrons in the nucleus. -
Ionic bonding and the properties of ionic compounds
Why do ionic compounds have high melting and boiling points?
Show the answer
A large amount of energy is required to overcome the strong electrostatic attractions between ions throughout the lattice -
Periodicity and the electron configurations of periods 2 and 3
State the electron configuration of carbon.
Show the answer
1s² 2s² 2p² -
Exothermic and endothermic reactions and enthalpy profiles
A reaction absorbs energy from its surroundings. What sign does its ΔH have?
Show the answer
Positive (ΔH > 0), indicating an endothermic reaction. -
Dynamic equilibrium and le Chatelier's principle
Why must a system be closed for dynamic equilibrium to be established?
Show the answer
No substances can enter or leave a closed system, so the reactants and products remain within the system to maintain equilibrium. -
IUPAC nomenclature and the alkyl groups
What principle determines which end of the carbon chain to start numbering from?
Show the answer
The chain is numbered so that substituents receive the lowest possible locant numbers. -
Alkanes: bonding, shape and boiling points
What is the shape around each carbon atom in an alkane?
Show the answer
Tetrahedral. -
Alkenes: the double bond, sigma and pi bonding, and shape
Why is there no free rotation about the carbon-carbon double bond in alkenes?
Show the answer
Rotation would break the sideways overlap of the p-orbitals that form the pi bond.
How the guide is worked
Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.
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Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
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Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
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Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.
Read the full method, the return schedule and the research behind it.
Look inside
Questions for a subtopic print together and the answers for that section print after them.
- Foundations in Chemistry284
- Bonding and Structure117
- Periodic Table and Energy177
- Enthalpy Changes89
- Chemical Equilibrium36
- Basic Concepts of Organic Chemistry82
- Core Organic Chemistry116
- Alkenes86
- Organic Synthesis52
- How Fast?107
- Physical Chemistry and Transition Elements101
- Acids, Bases and Buffers120
- and 5 more
- What is an ionic bond?
- What type of force holds ions together in an ionic lattice?
- Describe the structure of ionic compounds.
- Why do ionic compounds have high melting and boiling points?
- Why do solid ionic compounds not conduct electricity?
- In what physical states can ionic compounds conduct electricity, and why not in the solid state?
- Why do ionic compounds conduct electricity when molten?
- Why do ionic compounds conduct electricity when dissolved in water?
- Explain why ionic compounds are often soluble in polar solvents such as water.
- The strong electrostatic attraction between oppositely charged ions
- Strong electrostatic attraction
- Giant ionic lattice structures with ions arranged in a regular repeating three-dimensional pattern
- A large amount of energy is required to overcome the strong electrostatic attractions between ions throughout the lattice
- The ions are held in fixed positions within the lattice and cannot move
- Molten or dissolved in water, because ions are free to move; in the solid state ions are fixed in position and cannot carry charge
- The ions become free to move and carry charge
- The ions become free to move and carry charge
- Polar water molecules can surround and stabilise the ions
questions
Scroll sideways to turn through the pages.
Questions students ask first
I do OCR Chemistry. Is this the right specification?
OCR runs two A-Level Chemistry specifications. This guide is Chemistry A, H432. The other is Chemistry B, Salters, H433, which teaches the same chemistry through contexts and storylines and is organised completely differently.
The code is on your exam timetable and on the front of most endorsed textbooks. If yours says H433 you need the Chemistry B guide instead.
Does it cover all six modules?
Yes. 17 sections across the six modules, 160 subtopics, 1,913 questions. Module 2 Foundations in Chemistry is the largest single section at 284 questions, and Module 6 Organic Chemistry and Analysis runs to 184.
The full section list is here, grouped by module.
Are the calculations in it?
Yes, and they have their own subtopics rather than being folded into theory. Amount of substance and the mole, titration calculations, percentage yield and atom economy, enthalpy changes and Hess cycles, bond enthalpies, Kc and Kp, pH and Ka, buffer calculations, Born-Haber cycles, entropy and free energy, rate equations and half-lives, and electrode potentials and cell EMF.
What about the practicals and the PAGs?
The twelve practical activity groups are assessed two ways. The Practical Endorsement, Component 04, is marked by your teacher across the course and reported as a pass or not classified alongside your grade, so it is not in the guide.
Practical technique is also examined on all three written papers, and that content is in the guide: apparatus and technique, purification and recrystallisation, titration procedure, reflux and distillation, chromatography, testing for ions and functional groups, and the handling of uncertainty in results.
OCR A-Level Chemistry A Active Recall Guide
Every question paired with its answer, grouped by section and subtopic, ready to work in three passes.