The IB Chemistry Internal Assessment (IA) carries 20% of your final mark in IB DP Chemistry — making it the single most leveraged piece of work in the qualification. A strong IA can lift your overall grade by half a band; a weak one can prevent a grade 7 even with strong written-paper performance.

This guide goes deeper than our overview of IB IA topic ideas across all subjects to focus specifically on Chemistry: 25 topic ideas with research questions, the criteria broken down with what each one actually rewards, common pitfalls and what a high-scoring Chemistry IA looks like.

Free resource: Use Tutopiya’s IB DP Chemistry revision checklist to confirm your topic choice connects to a syllabus area you understand at depth.

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How the IB Chemistry IA is marked

The Chemistry IA is assessed against five criteria for a total of 24 marks:

Criterion	Marks	What it rewards
Personal engagement	2	Genuine curiosity, original thinking
Exploration	6	Focused research question, methodology, controlled variables
Analysis	6	Data treatment, uncertainty propagation, identification of trends
Evaluation	6	Conclusions linked to data, limitations, suggested improvements
Communication	4	Logical structure, clarity, scientific language and citations

A grade 7 Chemistry IA typically sits at 20–22/24. Chemistry IAs are slightly harder to top than Biology IAs because of the demand for uncertainty propagation through calculations in the Analysis criterion.

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The five criteria, broken down

Personal engagement (2 marks)

Examiners look for evidence that you chose the topic. A clearly stated reason, an original design choice, your voice in the write-up.

Exploration (6 marks)

The hardest criterion to score well on. Examiners want:

• A focused research question with named compounds, named technique, quantifiable variables.
• Background chemistry with relevant equations, mechanisms or thermodynamic principles.
• Methodological rationale — why this technique over alternatives.
• Controlled variables with explicit control method.
• Risk and ethical assessment — particularly important in Chemistry given hazardous reagents.

A research question like “How does temperature affect reaction rate?” will lose 4 of 6 marks. “How does temperature (20, 30, 40, 50, 60°C) affect the rate of reaction (1/t in s⁻¹) between 0.05 mol dm⁻³ Na₂S₂O₃ and 1.0 mol dm⁻³ HCl using the disappearing-cross method?” will earn most of the 6.

Analysis (6 marks)

Chemistry-specific demands:

• Raw data tables with units and uncertainties stated for every measured quantity.
• Processed data with uncertainty propagation — if you measured volume to ±0.05 cm³ and time to ±0.5 s, the propagated uncertainty in rate must appear.
• Graphs with error bars where relevant.
• Statistical or quantitative treatment — slope analysis, log-log plots for orders of reaction, Arrhenius plots.

Tip: uncertainty propagation is where most Chemistry IAs lose marks. Show the calculation explicitly.

Evaluation (6 marks)

Examiners want a conclusion explicitly linked to the data, realistic limitations with quantitative discussion, and specific improvements. Chemistry-specific evaluations should compare your value to a literature value where one exists.

Communication (4 marks)

Standard sections, 6–12 pages, full citations, IUPAC nomenclature, balanced equations with state symbols.

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25 IB Chemistry IA topic ideas with research questions

These are deeper and more specific than the 10 in our overview article.

Kinetics

1. Iodine clock variants — How does the concentration of H₂O₂ (0.1, 0.2, 0.3, 0.4, 0.5 mol dm⁻³) affect the rate of the iodine clock reaction?
2. Disappearing cross — How does temperature affect the rate of reaction between Na₂S₂O₃ and HCl?
3. Catalysis — How does CuSO₄ concentration affect the rate of reaction between zinc and dilute sulfuric acid?
4. Surface area — How does CaCO₃ particle size affect the rate of reaction with 1.0 mol dm⁻³ HCl?
5. Activation energy — Determining the activation energy of the reaction between Mg and HCl using an Arrhenius plot.

Thermodynamics

6. Heats of combustion — Comparing experimental enthalpy of combustion of methanol, ethanol and propan-1-ol with literature values.
7. Heats of neutralisation — How does the strength of an acid affect the enthalpy of neutralisation with NaOH?
8. Heat of solution — How does the cation (Li⁺, Na⁺, K⁺) affect the enthalpy of solution of the alkali metal chloride?
9. Hess’s Law — Determining the enthalpy of formation of MgO using Hess’s Law.

Equilibrium

10. Le Chatelier — How does temperature affect the equilibrium position of the FeCl₃/SCN⁻/FeSCN²⁺ system measured by absorbance?
11. Dissociation constant — Determining the Ka of acetic acid using a pH meter.
12. Solubility product — Determining Ksp of calcium hydroxide.

Electrochemistry

13. Voltaic cells — How does electrolyte concentration affect the cell potential of a Zn/Cu voltaic cell?
14. Electrolysis — How does current affect the mass of copper deposited at the cathode in CuSO₄ electrolysis?

Organic chemistry

15. Esterification — How does the type of carboxylic acid (methanoic, ethanoic, propanoic) affect the equilibrium yield of the ester with ethanol?
16. Saponification — How does the type of triglyceride affect the percentage yield of soap from the saponification reaction?
17. Aspirin synthesis — Optimising the percentage yield of aspirin from salicylic acid synthesis at varying temperatures.

Analytical chemistry

18. Vitamin C titration — How does cooking method (boiling, microwaving, raw) affect vitamin C content in green pepper?
19. Iron in cereal — Determining the iron content in iron-fortified breakfast cereals using colorimetry.
20. Caffeine extraction — How does brewing time affect caffeine concentration in tea?

Acids, bases and pH

21. Buffer capacity — How does buffer concentration affect resistance to pH change on addition of HCl?
22. Antacid effectiveness — Comparing the neutralising capacity of commercial antacid tablets per gram.
23. pH of acid rain — Investigating the effect of dissolved CO₂ concentration on water pH.

Applied chemistry

24. Hardness of water — Determining the hardness of tap water vs bottled water using EDTA titration.
25. Sunscreen UV absorbance — Comparing the UV-A absorbance of sunscreens with different SPF ratings using UV spectroscopy.

For broader topic ideas across the IB sciences, see our overview of IA topic ideas by subject.

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What a high-scoring Chemistry IA looks like

A 21/24 Chemistry IA shares six common features:

1. A specific, measurable, chemically meaningful research question with named compounds, named technique and quantifiable variables.
2. A method that controls 4–6 variables explicitly.
3. At least 5 levels of the independent variable, each repeated 3–5 times.
4. Uncertainty propagation through every calculated quantity.
5. A graph with error bars that displays the trend, with a slope or intercept that is interpreted chemically.
6. A comparison to a literature value where one exists, with the percentage error discussed.

Length: typically 9–11 pages.

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Common Chemistry IA pitfalls

Five errors come up consistently:

1. No uncertainty propagation. Stating uncertainties on raw measurements without propagating them through calculations costs 2–3 marks in Analysis.
2. Ignoring the literature value. Most quantitative IAs allow a comparison to a published value (e.g., enthalpies, Ka values). Skipping it loses Evaluation marks.
3. Insufficient repeats. Three repeats per IV level minimum; five is better.
4. Vague evaluation. “There were random errors” loses marks where quantitative discussion gains them.
5. Missing reaction equations. Balanced equations with state symbols are expected throughout. Missing them costs Communication marks.

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How to plan your Chemistry IA timeline

A useful Chemistry IA timeline runs over 3–4 months:

• Month 1: Topic selection, literature review, draft research question.
• Month 2: Method finalisation, pilot, full data collection.
• Month 3: Analysis (including uncertainty propagation), draft write-up.
• Month 4: Final revisions, teacher feedback, submission.

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Frequently asked questions

How long should an IB Chemistry IA be?

The IB recommends 6–12 pages of content. Most high-scoring IAs sit at 9–11 pages.

Do I need to use uncertainty propagation in my Chemistry IA?

Yes. The Analysis criterion specifically rewards uncertainty propagation through calculated quantities. This is one of the most-missed mark areas.

Should I include a literature comparison?

Where a literature value exists for a quantity you are measuring, yes — discuss your value against the literature value as part of Evaluation.

Can I do a Chemistry IA without a real-world context?

You can, but real-world contexts (e.g., antacid effectiveness, vitamin C in food) typically score higher on Personal Engagement than abstract investigations.

How many hours should I spend on the IA?

The IB allocates 10 hours of class time plus your independent work. High-scoring IAs typically involve 30–50 hours total.

What’s the most common reason Chemistry IAs lose Exploration marks?

Vague research questions and missing background chemistry (mechanisms, thermodynamic principles, kinetic theory).

Does the IA topic have to relate to the syllabus?

The topic must be in the scope of IB Chemistry but does not need to be directly from a syllabus topic. It can extend a syllabus area.

Can I do my IA on a topic from organic chemistry?

Yes — organic syntheses, esterification, soap production all make good IA topics. Be careful with hazards and ensure your school has appropriate equipment and supervision.

How does the IA mark connect to my final IB Chemistry grade?

The IA contributes 20% of your subject grade. See our IB DP Chemistry grade boundaries guide for how the IA mark is combined with Paper 1 and Paper 2 to award a 1–7 grade.

What’s the difference between a 17/24 and a 21/24 Chemistry IA?

The 21 has uncertainty propagation through calculations, a graph with error bars, a literature comparison and specific quantitative limitations. The 17 has all the same data but missing or vague treatment in those four areas.

Can I use a pre-existing experimental procedure?

You can adapt one — but the IA must include methodological reasoning (why this method, what alternatives existed, why your modifications). Following a textbook recipe verbatim costs Exploration marks.

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Last reviewed: 29 April 2026. The IB Chemistry IA is moderated against published criteria. Always work from the official IB Chemistry subject guide and your teacher’s feedback. For broader subject-IA ideas, see our IB IA topic ideas by subject overview.

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