IB Chemistry Data Booklet: How to Use It in Exams (2025 Guide)

If your child takes IB Chemistry, there is one little PDF they will reach for in almost every exam. It is called the IB Chemistry data booklet. It holds the constants, formulae, and tables they need so they don't have to memorise hundreds of numbers. Used well, it saves time and marks. Used badly, it slows a student down or hands them the wrong value.

This guide explains what the data booklet is, what is inside it, and exactly how to use it in each exam. We have written it for parents who want to understand the tool, and for students who want to stop fumbling through it under time pressure.

Quick answer: The IB Chemistry data booklet is the official reference document the IB gives every student during exams. It contains 23 sections, including the periodic table, key physical constants, bond enthalpies, and spectroscopy data. Since the 2025 syllabus (first exams May 2025), students can use the data booklet in all three exam papers — Paper 1A, Paper 1B, and Paper 2 — along with a calculator. The trick is knowing where each value lives so you find it fast.

What is the IB Chemistry data booklet?

The IB Chemistry data booklet is the official set of reference tables and constants students are given in every Chemistry exam.

Think of it as a cheat sheet that the IB writes for you. You are not meant to memorise the molar gas constant or the bond enthalpy of every bond. The IB knows that. So it puts those numbers in one clean document and hands it to every student in the world on exam day.

The same booklet is used for Standard Level (SL) and Higher Level (HL). There is one extra note: HL students use a few more rows in some tables, but the booklet itself is the same file. Every student gets a fresh, clean copy in the exam room. You cannot bring your own marked-up version.

The current version was written for the new Chemistry syllabus. Its first exams were in May 2025. The IB labels it "first assessment 2025". If you find an older booklet online marked "first assessment 2016", it is out of date. Some values and section numbers changed, so always use the 2025 edition.

If your child is just starting the course and feels lost with all the new resources, a specialist IB Chemistry tutor can walk them through the booklet section by section in the first few weeks. That early habit pays off for two years.

What's inside the IB Chemistry data booklet?

The IB Chemistry data booklet has 23 numbered sections, covering physical constants, the periodic table, energy data, and spectroscopy tables.

Here is the full list, in order, so you know exactly what is in the document and roughly where to look.

That looks like a lot. In practice, students lean on a small handful of sections again and again. We will get to those below.

Which exams can you use the data booklet in?

You can use the IB Chemistry data booklet in all three external exam papers under the 2025 syllabus: Paper 1A, Paper 1B, and Paper 2.

This is the single biggest change parents and students need to know. In the old syllabus, the data booklet was not allowed in Paper 1. Students only had a bare periodic table. Now the full booklet is on the desk for every paper.

You also get a calculator in every paper now. So the days of "no calculator, no booklet" Paper 1 questions are gone.

Here is how the three papers break down for the new course.

Paper 1 (1A and 1B together) lasts 1 hour 30 minutes at SL and 2 hours at HL. Paper 2 lasts 1 hour 30 minutes at SL and 2 hours 30 minutes at HL. The two external papers are worth 80% of the grade. The Internal Assessment (IA), called the Scientific Investigation, makes up the other 20%.

Because the booklet is now on the desk in Paper 1A, the multiple-choice questions have shifted. The IB no longer asks you to simply rank ionisation energies — you could just look them up. Instead, questions test whether you understand why the trend happens. Knowing the booklet well still helps, but it will not answer the question for you.

The new 2025 rule: the data booklet in Paper 1, explained

The headline change for 2025 is simple: the IB Chemistry data booklet is now allowed in Paper 1, where it used to be banned.

Why does this matter so much? In the past, Paper 1 had odd "trick" questions built around the fact that you had no booklet and no calculator. Students had to pick a calculation method instead of a number. Those questions are mostly gone.

Now Paper 1A gives you the full booklet and a calculator. So a question can ask for a real numerical answer. That is good news for students who panic at mental maths. But it raises the bar in another way. The exam now expects deeper understanding, because you can no longer score points just by recalling a value the booklet lists.

The lesson for students: do not treat the booklet as a safety net that removes the need to study. Treat it as a tool that rewards students who already know their chemistry and can move fast.

The most useful sections (and how to use them)

A handful of sections do most of the work in real exams. These are the ones worth knowing cold.

Section 1 — Some relevant equations. This is the list of formulae you are allowed to use. It includes things like the equation linking pH and hydrogen-ion concentration, the Gibbs free energy equation, and the equation for energy change in calorimetry. Students who learn where each formula sits save real time in calculation questions.

Section 2 — Physical constants. This holds the numbers you plug into those formulae: Avogadro's constant, the gas constant, the speed of light, and more. We give the key ones below.

Section 7 — The periodic table. The booklet's periodic table shows atomic numbers and relative atomic masses. Use these masses for every molar-mass calculation. Do not rely on memory for, say, the mass of chlorine — read it off the table.

Section 12 — Bond enthalpies. You need these for energy calculations using "bonds broken minus bonds formed". The values are averages, so your answer may differ slightly from a textbook. That is expected and not a mistake.

Section 19 — Standard reduction potentials. HL students use this table for electrochemistry, to work out cell potentials and predict whether a reaction happens. Reading the sign correctly is where marks are won or lost.

Sections 20, 21, and 22 — Spectroscopy. These are the IR, NMR, and mass-spectrometry tables. Students use them to work out the structure of an unknown compound. At HL, full structure identification from spectra is required, so these three sections come up a lot.

Key constants you'll use again and again

The constants in Section 2 of the data booklet are the values students reach for in almost every calculation paper.

You do not need to memorise these. But knowing they exist — and roughly where they sit — means you find them in seconds, not minutes. Here are the ones that come up most.

One value catches many students out. The IB defines standard temperature and pressure (STP) as 273.15 K and 100 kPa. So the molar volume of a gas is 22.7 dm³ mol⁻¹, not the 22.4 dm³ mol⁻¹ you may see in other textbooks. Always use the IB's 22.7 value in the exam.

A quick worked example: the booklet in action

Here is how a strong student moves through a typical calculation using only the data booklet and a calculator.

Say the question asks for the energy released when a fuel heats water. The student needs two things from the booklet. First, the specific heat capacity of water — that is 4.18 J g⁻¹ K⁻¹, in Section 2. Second, the equation linking energy, mass, and temperature change, which sits in Section 1.

The student writes the equation, reads the constant straight off the page, and plugs in the numbers. No memorising. No guessing. Just a calm, two-step lookup.

Now picture a gas question. The student needs to turn a volume of gas at STP into moles. They go to Section 2, find the molar volume of 22.7 dm³ mol⁻¹, and divide. One number, one step, done.

This is the whole point of the booklet. It removes the memory work so the student can spend their thinking time on the chemistry — choosing the right method and checking the answer makes sense. Students who practise this lookup habit early are calm in the exam. Students who hunt for values for the first time on exam day lose minutes they cannot spare.

Common mistakes students make with the data booklet

The most common data booklet mistakes are using the wrong value, the wrong units, or the wrong table — not a lack of knowledge.

Here are the slip-ups we see most often, and how to avoid each one.

Using memorised numbers instead of the booklet. A student "remembers" a bond enthalpy and writes it down. It is wrong. The booklet is right there — read it every time, even for values you think you know.

Ignoring units. The gas constant is in joules, but many answers need kilojoules. Mixing units is the number-one cause of "right method, wrong answer". Write units at every step.

Reading the wrong row or column. Tables in Sections 9, 12, and 19 are dense. Under time pressure, a student grabs the value one row up. Slow down for two seconds and check the label.

Forgetting bond enthalpies are averages. Energy answers using Section 12 are approximate. Students sometimes panic when their number does not match the mark scheme exactly. A small difference is fine if the method is correct.

Using the old booklet. Some past-paper packs online still bundle the 2016 booklet. A few values and section numbers changed for 2025. Practise only with the current edition.

For more on turning small habits like these into top grades, see our guide on how to score a 7 in IB.

How to practise with the data booklet before exams

The best way to master the data booklet is to keep it open beside you for every single practice question, from day one.

Do not save it for mock week. The students who flip through it fastest in the real exam are the ones who used it for two years. Here is a simple plan.

Print or open it every study session. Treat it like a textbook you always have nearby. Familiarity is the whole game.

Tab the sections you use most. When practising, note which section number you needed. Soon you will jump straight to "Section 12 for bond enthalpies" without thinking.

Do timed Paper 1A sets with the booklet. Since the booklet is now allowed in Paper 1, practise that way. Old papers that banned it will not match the new exam feel.

Use real IB past papers. Practising with official questions matters more than any worksheet. Our guide on where to find IB past papers shows the legal, official sources for every subject.

Check your answers against the mark scheme. When your number is off, ask whether it was a method error or a booklet error. That habit fixes both.

Students who want a clear picture of how these papers turn into a final grade can use our free IB score calculator to model different mark combinations.

Does the data booklet replace studying?

No. The data booklet gives you values and formulae, but it never gives you understanding, method, or the chemistry itself.

It is easy for a student to assume the booklet does the heavy lifting. It does not. The booklet tells you that the gas constant is 8.31. It does not tell you which equation to use, when to use it, or how to rearrange it. That part is on the student.

The 2025 changes actually make this clearer. Now that the booklet is in every paper, the exam tests deeper understanding rather than memory of values. So the booklet is best seen as a time-saver for students who already know their stuff — not a shortcut around learning it.

If your child is strong on concepts but loses marks on exam technique, one-to-one help often closes that gap fast. You can see how Educifly works with a free trial class before committing to anything.

Frequently asked questions

What is the IB Chemistry data booklet?

It is the official reference document the IB gives every Chemistry student in exams. It holds 23 sections of constants, formulae, and data tables — including the periodic table, bond enthalpies, and spectroscopy data — so students do not have to memorise hundreds of values.

Can you use the data booklet in IB Chemistry Paper 1?

Yes. Under the 2025 syllabus (first exams May 2025), the data booklet is allowed in all three papers: Paper 1A, Paper 1B, and Paper 2. This is new. In the old syllabus, Paper 1 only gave students a plain periodic table, with no booklet and no calculator.

Is the data booklet the same for SL and HL?

Yes. SL and HL students use the same data booklet file. HL students use a few extra rows in certain tables because their syllabus goes further, but the document itself is identical. Both levels get a clean copy in the exam.

How many sections are in the IB Chemistry data booklet?

There are 23 numbered sections in the 2025 edition. They run from "Some relevant equations" (Section 1) through to "Uncertainties" (Section 23), and include the periodic table, physical constants, bond enthalpies, reduction potentials, and IR, NMR, and mass-spectrometry data.

Where can I download the official IB Chemistry data booklet?

The official booklet is distributed by the IB to schools and is used in exams. Your child's Chemistry teacher or school IB coordinator can provide the current "first assessment 2025" version. Make sure any copy you use is the 2025 edition, not the older 2016 one, because some values and section numbers changed.

Why does the booklet say 22.7 dm³ instead of 22.4 dm³ for molar volume?

Because the IB defines standard temperature and pressure (STP) as 273.15 K and 100 kPa. At those conditions, one mole of an ideal gas takes up 22.7 dm³. The familiar 22.4 dm³ value uses a slightly different pressure (1 atm). Always use the IB's 22.7 value in the exam.

Do I need to memorise anything if I have the data booklet?

You still need to know your chemistry — reactions, mechanisms, definitions, and methods. The booklet gives you values and a list of formulae, but it does not tell you which formula to use or how to apply it. Think of it as a reference, not a substitute for studying.

Are bond enthalpy answers from the booklet always exact?

No. Section 12 lists average bond enthalpies, so energy calculations are approximate. Your answer may differ slightly from a textbook or mark scheme. That small gap is expected and will not cost marks if your method is correct.

Can the data booklet help with spectroscopy questions?

Yes, a lot. Sections 20, 21, and 22 give IR, ¹H NMR, and mass-spectrometry data. Students use these tables to identify unknown compounds. At HL, full structure identification from spectra is part of the course, so these sections come up often.

Is the data booklet allowed in the Internal Assessment?

The IA, or Scientific Investigation, is coursework done over time, not a timed exam, so students have access to all normal resources, including the booklet. The IA is worth 20% of the final grade and has a 3,000-word limit under the 2025 syllabus.

How is IB Chemistry assessed overall?

Two external papers make up 80% of the grade: Paper 1 (Paper 1A multiple choice plus Paper 1B data-based) is worth 36%, and Paper 2 (short and extended response) is worth 44%. The Internal Assessment is the final 20%. The data booklet and a calculator are allowed in all the written papers.

Does physics also have a data booklet?

Yes. IB Physics has its own data booklet, and IB Maths has a formula booklet. Each is specific to the subject. If your child takes more than one science, learning each booklet early is well worth the effort, and an IB Physics tutor can help them get comfortable with the physics version the same way.

Educifly is a boutique online tutoring practice for IB Diploma, IB MYP, and Cambridge and Edexcel IGCSE students. Our IB Chemistry specialists are subject experts who teach the same student every week — no rotation. Book a free trial class to see how a tailored plan can lift your child's Chemistry grade.