Let me be honest with you — picking an IB Chemistry IA topic is genuinely stressful. You’re sitting there, scrolling through experiment lists, second-guessing everything, wondering if your idea is “good enough.” And somewhere in the back of your mind, you’re calculating what a bad IA score would do to your final grade (it’s 20%, by the way — so yes, it matters).
But here’s what nobody really tells you upfront: the topic itself is rarely what separates a 5 from a 7. What separates them is how you think. Examiners read hundreds of IAs. They can tell within two pages whether a student genuinely engaged with their investigation or just copied a method from a textbook and hoped for the best.
So before we get into the list — promise yourself you’ll pick something you’re actually curious about.
What Examiners Are Actually Looking For
The IB marks your IA across five criteria: Personal Engagement, Exploration, Analysis, Evaluation, and Communication. Each one rewards a different kind of thinking.
Personal Engagement is probably the most misunderstood. It doesn’t mean writing “I have always loved chemistry” in your introduction. It means your research question reflects a genuine choice — something you thought about, not something assigned to you.
Exploration rewards a tight, well-defined question with a methodology that actually fits. Analysis wants correct data processing, good graphs, and propagated uncertainties. Evaluation is where most students lose marks — it’s not enough to list “human error.” You need to explain how specific errors affected specific results, and what you’d actually change.
Keep that in mind as you read through these ideas.
20 IA Ideas That Hold Up Under Scrutiny
Kinetics & Reaction Rates
1. Iodine clock reaction vs. temperature The dramatic color change gives you a clean, precise endpoint — no squinting at gas bubbles. From your data, you can build an Arrhenius plot and calculate activation energy. That kind of extended analysis tends to push scores higher.
2. Hydrogen peroxide decomposition with manganese dioxide as a catalyst: Collect oxygen volume over time, vary concentration, keep temperature fixed with a water bath. The catalysis discussion in your evaluation writes itself — and it’s genuinely interesting IB chemistry.
3. Marble chips and hydrochloric acid — surface area as the variable: Students dismiss this as too basic. It isn’t if you execute it well. Use a gas syringe instead of water displacement, run multiple trials, and write a proper error analysis. Examiners reward precision over complexity.
4. pH effect on vitamin C oxidation rate: This one has real-world relevance — think food preservation, orange juice, packaging. Titration-based data gives you numbers to work with, and the personal engagement angle practically writes itself.
Electrochemistry
5. Electrolyte concentration and EMF in a zinc-copper galvanic cell: If you’re comfortable with logarithms, this links directly to the Nernst equation. Prepare your solutions carefully, use a reliable digital voltmeter, and your analysis section will have real depth.
6. Electrode material and electrolysis efficiency in copper sulfate solution: Swap cathode materials, measure deposited mass using an analytical balance, and apply Faraday’s laws. Clean data, clear trends.
Acid-Base Chemistry
7. Buffer capacity at varying concentrations of an acetate buffer: You’ll need a pH meter you trust, but this is a topic where genuinely sophisticated analysis is within reach for most students. Error bars on your graph aren’t optional here — they’re part of the story.
8. Enthalpy of neutralization: weak acid vs. strong base, at different neutralization levels: A polystyrene cup calorimeter, a thermometer, and careful technique. Heat loss is your biggest systematic error — address it properly, and your evaluation section becomes a strength rather than a weakness.
9. pH and conductivity relationship in acetic acid solutions: Less common than the usual acid-base topics, which works in your favor. It demonstrates an understanding of weak acid equilibrium that examiners notice.
Thermochemistry
10. Alcohol chain length and enthalpy of combustion: Clear trends, published data to compare against, and a discussion of incomplete combustion that most students actually understand. Use a spirit burner, draft shield, and copper calorimeter — and be honest about your heat losses.
11. Concentration and enthalpy of dissolving ammonium nitrate: The cooling effect is visible and surprising the first time you see it. The entropy discussion you can build around it adds real conceptual depth to your analysis.
Chromatography & Analytical Methods
12. Natural plant dyes analyzed by paper chromatography: Pick plants that mean something to you — from your garden, your kitchen, wherever. Rf values give you quantitative data, and the polarity discussion underpins everything. Strong personal engagement potential here.
13. UV absorbance of natural vs. commercial sunscreens using a colorimeter: Timely, relatable, and analytically rich. If your school has spectrophotometry equipment, this one is worth serious consideration.
Enzyme Chemistry
14. Temperature and amylase activity on starch: Iodine as your indicator, a clear color change, a rate-vs-temperature curve. The denaturation discussion at higher temperatures gives your evaluation real scientific meat.
15. pH and catalase activity using hydrogen peroxide: Oxygen production was measured by volume over time. Run it at five or six pH values, find the optimum, and discuss why it shifts. Statistical treatment of your data here can really elevate the score.
Equilibrium
16. Temperature effect on the equilibrium constant of cobalt(II) chloride: The pink-to-blue color shift is genuinely striking, and a colorimeter turns it into quantitative data. This works best in schools with spectrophotometry access, but it’s one of the stronger equilibrium IAs available.
17. Ion concentration and the solubility product of calcium sulfate: More demanding, but if you’re comfortable with Ksp calculations, the analysis section rewards that comfort. Real-world connection to water hardness adds context.
Corrosion & Materials
18. Salt concentration and the rate of iron corrosion: Iron nails, saltwater solutions of varying concentrations, mass loss over time. Simple to set up, but the galvanic cell discussion in your evaluation shows theoretical depth. Practical and grounded in real-world chemistry.
Organic Chemistry
19. Acid catalyst concentration and ester yield in Fischer esterification: Quantitative yield calculations from a school-level reaction. The analysis section benefits enormously from percentage yield comparisons and a discussion of equilibrium position.
20. Carbon chain length and melting point in fatty acids: You’ll need access to pure samples, but the trends are consistent, and the explanation for intermolecular forces is solid. A good choice if your school has the reagents available.
Before You Commit to a Topic — Read This First
Narrow your research question until it hurts. “How does temperature affect reaction rate?” is not a research question. “How does temperature, varied between 10°C and 50°C, affect the rate constant of the sodium thiosulfate reaction with hydrochloric acid?” — that’s a research question.
Run a pilot experiment. Always. Not to collect data, but to check your variable range makes sense, your method is actually executable in your lab, and your results won’t flatline at one end of your graph.
And collect enough data points. Five to seven values along your independent variable axis give you a graph worth analyzing. Three points give you a line that proves nothing.
How The Princeton Review Can Help
Understanding the criteria is one thing. Actually applying them to your specific investigation — with your data, your errors, your school’s equipment — is something else entirely.
The Princeton Review’s IB tutors work specifically within the IB framework, which means they understand how examiners think, what language scores well in evaluations, and where students typically lose marks they didn’t expect to lose. Whether you’re still shaping your research question or sitting on a completed draft that needs a sharper eye, our one-on-one IB coaching is structured around the actual assessment criteria. For students serious about hitting a 7, that targeted support is worth it.
One Last Thing
The IAs that score 7s aren’t always the most sophisticated experiments. They’re the ones where the student clearly understood what they were investigating, was honest about what went wrong, and could explain their results in terms of actual chemistry — not just describe what happened.
That combination of rigor and genuine curiosity is harder to fake than most students think. So don’t try to fake it. Pick something real, dig into it properly, and let the science do the work.
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