How to Revise for IB Chemistry (SL and HL)

The IB Chemistry course changed for exams from May 2025. The options and Paper 3 are gone, the content is reorganised into Structure and Reactivity, and Paper 1 now has a data-based section. Much of the revision advice online was written for the old course, and some of it is now wrong.

This guide covers how the current course is examined, what the research on memory says about how to revise for it, and where SL and HL students should spend their time. Every assessment detail here is taken from the IB Chemistry guide for first assessment 2025, and the studies are listed under Sources at the end.

Know how the course is examined

The assessment is the same shape at SL and HL. HL papers are longer and include the additional higher level material.

Paper 1 lasts 1 hour 30 minutes at SL and 2 hours at HL, and you sit 1A and 1B together without a break. Three things in the guide shape how you should revise.

Half of every paper is analysis. The IB weights each paper roughly 50% on knowing and applying (AO1 and AO2) and 50% on analysing, evaluating and synthesising (AO3). Knowing the content gets you half the marks. The rest comes from using it on data, procedures and situations you have not seen before.

Calculators and the data booklet are allowed in both papers. This includes Paper 1A, which was calculator-free on the old course. If you are working from old notes or older revision sites, ignore advice about non-calculator multiple choice.

There is no negative marking in Paper 1A. Never leave a multiple-choice question blank.

Revise the way memory works

Most students revise by rereading notes, highlighting and redoing questions they already know the answers to. It feels productive because the material becomes familiar. Familiarity is not the same as being able to produce an answer under exam conditions, and the research on this is unusually consistent.

A 2013 review by John Dunlosky and colleagues rated ten common study techniques by the strength of the evidence behind them. Two came out on top: practice testing and distributed practice. Rereading and highlighting came out near the bottom. The sections below are built on the techniques that work.

Test yourself instead of rereading

Retrieval practice means closing your notes and trying to produce the answer from memory before checking it. In a well-known 2006 experiment, Henry Roediger and Jeffrey Karpicke found that students who tested themselves on a passage remembered much more of it a week later than students who spent the same time rereading it, even though the rereaders felt more confident.

The effort of retrieval is the point. Robert Bjork calls this a desirable difficulty: conditions that make study feel harder in the moment and make the learning last.

For IB Chemistry, retrieval looks like this:

• Blank-page recall. Pick a subtopic, such as Structure 2.2 or Reactivity 3.4, and write down everything you can. Then check against the guide and your notes, and fill the gaps in a different colour.
• Mechanisms and structures from memory. Draw each reaction mechanism with every curly arrow, lone pair and intermediate. Draw Lewis structures and predict shapes without looking anything up.
• Multiple-choice questions. These are quick retrieval, and Paper 1A is itself multiple choice. Most of the value is in working out why each wrong option is wrong.
• Attempt before you look. When you get stuck on a worked problem, write down your best attempt before you read the solution. Generating an answer, even a wrong one, makes the correct one easier to remember afterwards.

Space it out and mix it up

A topic crammed in one long session feels mastered and fades within days. The same time spread across several sessions, with gaps long enough that you have started to forget, produces memory that lasts much longer. A large 2006 meta-analysis by Nicholas Cepeda and colleagues found this spacing effect across hundreds of studies.

In practice, return to each topic after a few days, then after a week, then after a few weeks. A topic you found easy should still come back, just less often. A topic you got wrong should come back sooner.

Mix topics within a session as well. Interleaving, practising different kinds of problem in one session instead of one kind at a time, makes you work out which idea a question needs. Doug Rohrer and Kelli Taylor showed this in maths: students who practised mixed problems scored far higher on a delayed test than students who practised in blocks.

The new IB course makes this easy to plan. The guide includes linking questions that connect understandings across the course, and its stated aim is a networked understanding of chemistry. Use them to pair topics: ionisation energy with reactivity down group 1, bond enthalpy with energy cycles, equilibrium with acid strength. Paper 2 questions move between topics in the same way.

Use the guide as your checklist

The IB Chemistry guide divides the course into 22 subtopics across Structure 1 to 3 and Reactivity 1 to 3. Each subtopic is broken into understandings, with guidance on what is and is not assessed. Every exam question traces back to one of them.

Go through each understanding and rate yourself honestly:

• I can do this cold, without notes.
• I recognise it but would need to check something.
• I have not covered this properly.

Do the ratings before you check, and then test them. Psychologists call the match between how sure you feel and how often you are right calibration, and most students are overconfident on exactly the topics they have reread most. A self-rating that a quick test then corrects tells you where your time should go.

If you would rather not build the list by hand, PinPoint has every understanding in the guide split into individual statements, each with a confidence dot that fades when it is due for review.

Hunt for misconceptions, not just gaps

A gap is something you do not know. A misconception is something you believe that is wrong. Misconceptions do more damage, because you answer confidently and lose the mark without noticing.

Some common ones in IB Chemistry:

• Thinking a catalyst shifts the position of equilibrium, rather than only increasing the rate at which equilibrium is reached.
• Thinking bond breaking releases energy.
• Confusing a strong acid with a concentrated one.
• Thinking a covalent bond breaks when a simple molecular substance melts or boils.
• Starting a curly arrow from an atom instead of from a lone pair or a bond.

There is good news in being confidently wrong. Studies of the hypercorrection effect, starting with Brady Butterfield and Janet Metcalfe in 2001, found that errors made with high confidence are more likely to be corrected after feedback than errors made while guessing. Being surprised makes you pay attention. So when you get something wrong, write one sentence on the reasoning that led you there and why it fails. That sentence is what stops you making the same error in the exam.

PinPoint is built around this. Every wrong option in its IB Chemistry question bank names the misconception behind it, so a wrong answer tells you which belief to fix, not just that you were wrong.

Ask why, not just what

After you get an answer right, ask yourself why it is true. Why does first ionisation energy dip from group 2 to group 13? Why is the conjugate base of a weak acid itself a base? Explaining the reason to yourself, sometimes called elaborative interrogation, connects a fact to what you already know. It also prepares you for "Explain" questions, which reward reasons, not conclusions.

When you are stuck, use hints in order of size. Look for a pointer to the right idea first, then the first step, and only then a full worked example. Worked examples are an efficient way to learn a new kind of problem, and they work best once you have had a genuine attempt yourself.

These principles are what Pin, PinPoint's AI study coach, is built on. Pin asks for your attempt before it explains, gives one hint at a time and moves to a worked example after two genuine tries. It asks how sure you were, and treats "felt sure" and wrong as the most important thing to fix. A few days after you fix a point, it brings that point back as a cold question, paired with a neighbouring point.

Treat the Tools as content

Paper 1B is data-based questions and questions on experimental work. It draws on the Tools and Inquiry sections of the guide, which many students treat as background to the IA and never revise. Revise them like any other topic.

• Tool 1, experimental techniques. Know the purpose and practice of the techniques the guide lists: standard solutions and dilutions, titrations, calorimetry, chromatography, distillation and reflux, colorimetry, electrochemical cells, recrystallisation and melting point determination. Be ready to say why each step is done and what goes wrong if it is skipped.
• Tool 3, mathematics. Percentage error and percentage uncertainty, propagating uncertainties through calculations, significant figures, logarithms and scientific notation. HL adds exponential functions and propagating uncertainties through exponents.
• Graphs. Plot with sensible scales, draw lines and curves of best fit, find gradients and intercepts, interpret uncertainty bars, and use R² to judge how well a trend line fits.

Practise reading graphs and tables you have never seen. A rate graph you know well from class is recall. A new one is analysis, and analysis is what earns the AO3 marks.

Learn the command terms

The guide defines every command term, and mark schemes follow the definitions closely. A few that are often mixed up:

• State asks for a short answer, with no explanation or calculation.
• Outline asks for a brief account; Describe asks for a detailed one.
• Explain asks for a detailed account that includes reasons or causes.
• Deduce asks you to reach a conclusion from the information given.
• Determine asks for the only possible answer.
• Suggest asks you to propose a reasonable answer, usually in an unfamiliar context.
• Evaluate asks you to weigh up strengths and limitations.

A common way to lose marks is to give a correct fact when the question asked for a reason. Underline the command term before you start writing.

Make calculations automatic

Calculations appear across both papers: amount of substance and gas laws, energy cycles, equilibrium constants, rates, pH and electrochemical cells. They are the most reliable marks on the paper if your method is fluent.

• Show every step. Mark schemes give error carried forward (ECF) credit, so a slip early on does not cost you every later mark if your working is visible.
• Keep full precision through the working and round only the final answer, to a number of significant figures that matches the data.
• Write units at every step.
• Know where everything is in the data booklet. You get a clean copy in both papers, so practise finding values quickly rather than memorising them.
• Check whether the size of your answer is sensible before you move on.

If you take HL

HL is 240 teaching hours against 150 for SL, and the extra content is not spread evenly. The guide's recommended hours almost double for Reactivity 3, the mechanisms of chemical change (24 hours at SL, 45 at HL), and for Structure 3, the classification of matter (16 at SL, 31 at HL). HL Paper 2 is 2 hours 30 minutes for 90 marks.

Give the HL-only material its own review cycle rather than fitting it in around the SL content. Organic mechanisms, stereoisomerism, and the HL energetics and equilibrium calculations come up in long Paper 2 questions, often combined with SL content.

Use past papers carefully

The current course was first examined in May 2025, so only a few exam sessions in the new format exist. Older papers are still useful practice for content that carried over, but they include option topics that no longer exist in that form, and they have no Paper 1B. Check each older question against the current guide before you count it as practice.

In the final weeks, sit full papers under timed conditions with a data booklet and calculator. Afterwards, sort every lost mark into one of three groups: did not know the content, knew it but misapplied it, or misread the question or ran out of time. Each needs a different fix, and the pattern across a few papers tells you what to work on next.

Do not let the IA crowd out revision

The scientific investigation is worth 20% of your grade at both SL and HL. It is a report of up to 3,000 words, marked out of 24 on four equally weighted criteria: research design, data analysis, conclusion and evaluation. The guide allocates about 10 hours to it.

The IA is not revised for, but it competes with revision for time, so agree its deadlines with your teacher and plan around them. The skills overlap with Paper 1B: identifying variables, processing uncertainties and evaluating a method are what the data-based questions test.

A simple weekly structure

If you want a starting point:

1. Two or three short retrieval sessions on the understandings you rated weakest, with topics mixed rather than blocked.
2. One session on older topics you have not seen for a couple of weeks.
3. One data-based practice session: an unfamiliar graph or table, with the uncertainty and evaluation questions it raises.
4. One timed section or paper, marked strictly against the mark scheme.
5. Fifteen minutes updating your checklist based on what the week showed you.

As the exam gets closer, do more full papers and less new content.

Frequently asked questions

How is IB Chemistry assessed?

At both SL and HL there are two exam papers and an internal assessment. Paper 1 (multiple choice in Paper 1A, data-based questions in Paper 1B) is worth 36%, Paper 2 (short-answer and extended-response) is worth 44%, and the scientific investigation is worth 20%.

Can you use a calculator in IB Chemistry Paper 1?

Yes. On the course first examined in 2025, calculators are permitted in both Paper 1 and Paper 2, and every student has a clean copy of the data booklet. Paper 1A was calculator-free on the old course, so older advice on this is out of date.

What is the difference between IB Chemistry SL and HL?

HL has 240 recommended teaching hours against 150 for SL, with extra content in all six topics. The biggest increases are in Reactivity 3, the mechanisms of chemical change, and Structure 3, the classification of matter. HL papers are longer: Paper 1 is 2 hours for 75 marks and Paper 2 is 2 hours 30 minutes for 90 marks, against 1 hour 30 minutes each at SL.

Are old IB Chemistry past papers still useful?

Partly. Papers from before 2025 cover much of the same chemistry, but they include option topics that no longer exist in that form and have no Paper 1B. Check each question against the current guide before using it for practice.

What is the most effective way to revise IB Chemistry?

Test yourself rather than rereading, space your revision of each topic over weeks, and mix topics within a session. Practise with unfamiliar data, because half the marks on each paper are for analysis and evaluation.

How much is the IB Chemistry IA worth?

The scientific investigation is worth 20% of the final grade at both SL and HL. It is marked out of 24 on four criteria worth 6 marks each: research design, data analysis, conclusion and evaluation.

Revising with PinPoint

PinPoint covers the whole IB Chemistry guide at SL and HL, built for the retrieval, spacing and misconception work this guide describes, with Pin there when you get stuck.

Start revising IB Chemistry

Sources

• International Baccalaureate (2023). Diploma Programme Chemistry guide, first assessment 2025. Assessment outline, syllabus outline, tools and glossary of command terms.
• Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J. and Willingham, D. T. (2013). Improving students' learning with effective learning techniques. Psychological Science in the Public Interest, 14(1), 4–58.
• Roediger, H. L. and Karpicke, J. D. (2006). Test-enhanced learning: taking memory tests improves long-term retention. Psychological Science, 17(3), 249–255.
• Cepeda, N. J., Pashler, H., Vul, E., Wixted, J. T. and Rohrer, D. (2006). Distributed practice in verbal recall tasks: a review and quantitative synthesis. Psychological Bulletin, 132(3), 354–380.
• Rohrer, D. and Taylor, K. (2007). The shuffling of mathematics problems improves learning. Instructional Science, 35, 481–498.
• Butterfield, B. and Metcalfe, J. (2001). Errors committed with high confidence are hypercorrected. Journal of Experimental Psychology: Learning, Memory, and Cognition, 27(6), 1491–1494.
• Bjork, E. L. and Bjork, R. A. (2011). Making things hard on yourself, but in a good way: creating desirable difficulties to enhance learning. In Psychology and the Real World, 56–64. Worth Publishers.