How DP Chemistry Is Assessed: Revision Notes

Condensed for quick recall of how the course is assessed. For the full subject overview, use the IB DP Chemistry subject overview.

The assessment split

Component	Weight	What it involves
Paper 1	36%	Multiple-choice, short-answer and data-based questions across the syllabus
Paper 2	44%	Multiple-choice, short-answer and extended-response questions on structure and reactivity
Internal assessment	20%	An individual scientific investigation, up to 3,000 words

External (80%) + internal (20%), same split at SL and HL — papers differ in length/demand, not weighting.

The data booklet

A clean copy of the chemistry data booklet (constants, formulae, and data such as relative atomic masses) is provided to every candidate for every paper, at both SL and HL. This is deliberate: the guide states it maintains the emphasis on interpretation over memorisation, so revision time is better spent practising how to select and use the right piece of supplied data than memorising it. Anything printed in the data booklet – for example the Avogadro constant and relative atomic masses to two decimal places – does not need to be committed to memory; know instead which page it is on and how to use it correctly.

The structure-and-reactivity framework

Chemistry is organised around two linked concepts: structure determines how matter reacts, and reactions in turn transform structure. Both papers draw questions across this framework rather than testing topics as standalone blocks — a reason to revise connections between topics, not just topics in isolation.

IA vs. collaborative sciences project

The graded IA is an individual investigation. The interdisciplinary collaborative sciences project (with peers from other group 4 subjects) builds skills but is not itself graded — keep these separate in your revision/coursework planning.

Command terms and how each paper uses them

Both papers draw their questions from the same command-term glossary used across all DP sciences – state, define, identify and describe at the lower end (recall and straightforward description), through explain, compare, deduce and suggest in the middle, up to evaluate, discuss and justify at the top, where a reasoned judgement or synthesis across multiple pieces of evidence is required. Paper 1’s multiple-choice, short-answer and data-based questions lean more heavily on the lower and middle tiers; Paper 2’s extended-response questions, worth almost half the external mark, more often reach the top tier – so revision time spent specifically practising evaluate and discuss style answers (weighing evidence, acknowledging limitations, reaching a justified conclusion) pays off disproportionately for Paper 2.

The internal assessment in more depth

The IA report is assessed against a set of criteria covering the whole investigative process, not just the final result: formulating a focused, testable research question; designing a method capable of generating enough reliable data to answer it; recording and processing that data appropriately (including uncertainty and error where relevant); and evaluating the investigation’s strengths and weaknesses, including specific, actionable suggestions for improvement rather than generic ones. A common weakness examiners note is an evaluation section that lists limitations without connecting them concretely to how they affected the specific results obtained – a strong evaluation ties each limitation back to its actual impact on the data, and proposes a specific, feasible improvement rather than a vague one like “use more accurate equipment.”

How Chemistry’s assessment compares to its sibling sciences

DP Biology and DP Physics follow the same overall assessment architecture – two external written papers plus an individually graded internal assessment, together with the ungraded collaborative sciences project – but each subject’s papers are built around its own organising framework rather than Chemistry’s structure-and-reactivity pairing. If you are also studying another Group 4 science, recognising that the shape of assessment (external papers plus IA plus collaborative project) transfers directly, while the specific organising concepts tested do not, helps avoid wasted revision time trying to map one subject’s framework onto another’s.

How SL and HL differ

The percentage weightings for Paper 1, Paper 2 and the internal assessment are identical at SL and HL – what changes between levels is the depth and breadth of syllabus content examined and the demand of the questions asked, not the structural balance between components. This means a revision plan built around the assessment weightings above applies equally at either level; only the underlying content coverage needs adjusting for HL’s additional material.

Why 80/20 rather than an even split

The 80% external / 20% internal balance is deliberately weighted toward the two written papers because the DP sciences model treats the IA as a focused test of practical and investigative skill on one self-chosen topic, while the papers are needed to sample understanding across the whole syllabus breadth – a single IA, however well executed, cannot demonstrate the same breadth of content mastery that two full papers can assess. Keeping this in mind when allocating revision time – proportionally more time on paper-style practice than on IA polishing once a solid IA draft exists – reflects where the majority of the final grade actually sits.

Self-test

1. What two linked concepts organise the whole Chemistry syllabus?
2. What are Paper 1 and Paper 2 weighted at?
3. Why should revision connect topics rather than treat them as standalone blocks?
4. What is the maximum word count for the internal assessment report?
5. Name one common weakness examiners note in a weak IA evaluation section.
6. Does the balance between Paper 1, Paper 2 and the IA change between SL and HL?

Answers: 1. Structure and reactivity. 2. Paper 1: 36%, Paper 2: 44%. 3. Because both papers draw questions across the structure-and-reactivity framework rather than testing each topic in isolation, so understanding how topics connect is directly rewarded. 4. 3,000 words. 5. Listing limitations without connecting them concretely to their actual impact on the results obtained, or proposing only vague improvements. 6. No – the percentage weightings are identical at both levels; only the depth and demand of the content examined changes.

Official syllabus

International Baccalaureate Organization, Chemistry guide, Diploma Programme, first assessment 2025 (published February 2023, updated May 2023) – copy consulted via a school-hosted mirror, not ibo.org. The same source is cited by the full syllabus guide and the subject overview.