IB Chemistry data booklet explained
The IB Chemistry data booklet (first assessment 2025) is the reference you use in every Chemistry exam, at SL and HL. It has 24 numbered sections: a page of equations, constants and units, the periodic table, and tables of data such as bond enthalpies, standard electrode potentials and spectroscopy values.
The IB says each student must have a clean copy during the examinations, and that it is there so the course can stress interpretation and application rather than memorising. This page explains what each section is for. It does not reproduce the booklet; your school downloads the official copy from the IB.
The 24 sections and what they are for
| Section | What is in it | How to use it |
|---|---|---|
| 1. Some relevant equations | About 20 equations: , , , , , atom economy, Gibbs energy, the Arrhenius equation, pH and . | Your first stop for any calculation. Check the exact form, for example the two Arrhenius forms. |
| 2–4. Constants, multipliers, units | Physical constants such as , and the Faraday constant; SI prefixes; conversions, STP (273.15 K and 100 kPa) and SATP. | Note the molar volume of a gas at STP: 22.7 dm³ mol⁻¹, not 22.4. |
| 5. The electromagnetic spectrum | Regions of the spectrum by wavelength. | Link wavelength to energy for spectroscopy questions. |
| 6–7. Names of the elements and the periodic table | Every element’s name, symbol, atomic number and relative atomic mass. | Take relative atomic masses from here for every moles calculation. |
| 8–10. Properties of the elements | Melting and boiling points, first ionization energy, electron affinity, electronegativity, and atomic and ionic radii. | Use the numbers to explain periodic trends rather than describing them vaguely. |
| 11–12. Bond lengths and bond enthalpies | Covalent bond lengths, and bond enthalpies or average bond enthalpies at 298.15 K. | Estimate enthalpy changes from bonds broken minus bonds made; the answer is approximate because the values are averages. |
| 13–14. Thermodynamic data and enthalpies of combustion | Standard enthalpies of formation and other data for selected compounds; enthalpies of combustion. | Use these with the equations in section 1 for Hess’s law and Gibbs energy problems. |
| 15. Colour wheel | Wavelengths of the visible spectrum on a colour wheel. | Find the complementary colour when explaining why a transition metal complex is coloured. |
| 16–17. Lattice enthalpies and the bonding triangle | Experimental lattice enthalpies at 298.15 K, and the van Arkel–Ketelaar triangle. | Place a compound on the triangle from electronegativity values to classify its bonding. |
| 18. Acid–base indicators | Indicators with their pH ranges and colours. | Choose an indicator whose range sits on the steep part of the titration curve. |
| 19. Standard reduction potentials | Half-equations and values at 298.15 K. | Find the cell potential and predict whether a redox reaction is spontaneous. |
| 20–22. Infrared, ¹H NMR and mass spectral data | Characteristic IR absorptions, NMR chemical shifts, and common fragments lost in mass spectrometry. | Use them together to identify an unknown compound. |
| 23. Uncertainties | How uncertainties combine for sums, products and powers (added in February 2024). | For data-based questions and your internal assessment. |
| 24. References | The published data sources the values come from. | Not needed in the exam. |
What the booklet does not give you
Section 1 does not include , the expressions for and , or percentage yield, so learn those. It gives you values, not definitions: you still need to define terms such as first ionization energy or electronegativity in words.
It also does not tell you which data to use. Questions often reward choosing the right table, for example using standard enthalpies of formation from section 13 rather than average bond enthalpies from section 12 when the data are available.