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.

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.

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.

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.

Yes. Free radical substitution, electrophilic addition and the Markownikoff rule, nucleophilic substitution, elimination, electrophilic substitution in aromatic compounds, nucleophilic addition to carbonyls, esterification and hydrolysis, and the reagents and conditions for each.

Spectroscopy has its own section of 88 questions covering mass spectra, infrared and both carbon-13 and proton NMR.

Unified Chemistry can set any content from the specification in an unfamiliar context and asks about experimental method, planning and the analysis of data. Holding the whole specification at once is a recall problem before it is a technique problem, and the guide is the whole course in one file.

About twenty minutes for one subtopic, all three steps. Sections vary from 36 questions to 284, so work by subtopic and the size of the section stops mattering.

Write. You write the paper by hand, and step 2 only works written out because that is where the wording and the working are corrected. This matters more in chemistry than in most subjects, because a mark scheme wants a specific reagent and a specific condition rather than the gist.

The method page sets out the evidence.

OCR A-Level Chemistry A is linear, so everything is examined at the end of Year 13. Work each subtopic in the week it is taught, or start a first full pass in the January of Year 13 and run returns from there. The guide covers both years from the first day of Year 12.

Yes. The method puts the specification into memory. Past papers train the multi-step calculation under time, the unfamiliar context and the extended response. OCR publishes them free.

A PDF, emailed on purchase. The questions for a section print together and the answers for that section follow directly after them, so covering the answers is a matter of not turning the page.

A PDF of 1,913 exam-style questions covering the whole of OCR A-Level Chemistry A, with the answers printed after each section.

It is not a textbook and does not teach content for the first time. It is the tool for moving taught content into memory and for proving whether it went in.

There should be handwritten answers on paper, and three passes over the same questions. The method produces two numbers each session, the score on the first closed-book pass and the score on the third. Those two numbers tell you more than how long they sat at the desk.

Rereading notes and highlighting are the two most common revision activities, and Dunlosky and colleagues rated both low utility in their 2013 review of ten techniques. Chemistry punishes this harder than most subjects, because a half-remembered reagent scores nothing.

The method page sets out the alternative and the research behind it.

£8.00 for the whole specification. An endorsed OCR A-Level Chemistry textbook is usually £30 to £40, and covers one of the two years.

Find the specification code. OCR runs Chemistry A (H432) and Chemistry B Salters (H433). They teach the same chemistry in a completely different order and the guides are not interchangeable. This one is H432.

160 subtopics at roughly twenty minutes each is about 53 hours for a full first pass. Spread across Year 13 that is under two hours a week, and the returns afterwards are three to five minutes each.

Past papers, which OCR publishes free, and their own notes or textbook for anything not yet taught. Nothing else is required to run the method.

With Module 2, Foundations in Chemistry. It is assessed on all three papers and everything else assumes it, including every calculation in the course. After that, whichever module their next assessment covers.