Choosing among possible IB Chemistry IA topics is not about finding the most original or complicated experiment. The strongest topic lets you collect reliable quantitative data, apply relevant chemistry, control important variables, and evaluate meaningful limitations within your school's time, equipment, and safety constraints.
This guide presents practical topic categories, explains how to develop a focused research question, and identifies why supervisors reject proposals. Each example is a starting point. Your final investigation must reflect your own decisions, pilot testing, available apparatus, and teacher-approved risk assessment.
What makes an IB Chemistry IA topic workable?
The current internal assessment is called the scientific investigation. According to the official IB Chemistry subject brief, it contributes 20% of the final grade at SL and HL, is allocated approximately 10 hours, and has a maximum report length of 3,000 words.
The investigation uses four equally weighted criteria:
| Criterion | Marks | What the topic must support |
|---|---|---|
| Research design | 6 | A focused question and reproducible methodology |
| Data analysis | 6 | Suitable processing, uncertainties, and presentation |
| Conclusion | 6 | An evidence-based answer connected to chemistry |
| Evaluation | 6 | Specific limitations and realistic improvements |
The IB Chemistry curriculum update confirms that Conclusion and Evaluation together provide half the marks. A simple experiment with identifiable limitations can therefore be stronger than an elaborate procedure producing inconsistent data.
A workable topic usually has:
- one clearly defined independent variable
- a quantitative dependent variable, such as rate, absorbance, concentration, pH, voltage, mass change, or enthalpy change
- control variables that can realistically remain constant
- enough measurements and repeats to identify a trend
- chemical theory that predicts or explains the relationship
- equipment precise enough to detect the expected change
- a safe procedure and manageable disposal plan
Using at least five independent-variable values and several repeats is often sensible, but it is advice rather than an IB rule. The appropriate amount of data depends on the relationship being investigated and should be justified.
Safe and feasible IB Chemistry IA topic categories
No experiment is automatically safe. Risk depends on concentration, quantity, apparatus, temperature, exposure, and local rules. The American Chemical Society's laboratory safety guidance recommends RAMP: recognize hazards, assess risks, minimize risks, and prepare for emergencies. Obtain approval before beginning practical work and follow your teacher's disposal instructions.
Kinetics and reaction rates
Kinetics investigations work well because time, gas volume, or absorbance can be recorded repeatedly. Possible systems include clock reactions, hydrogen peroxide decomposition, acid-carbonate reactions, and food-dye fading.
| Starting idea | Independent variable | Dependent variable | Main issue |
|---|---|---|---|
| Iodine clock | Temperature | Time or calculated rate | Mixing and temperature control |
| Hydrogen peroxide decomposition | Catalyst concentration | Initial oxygen-production rate | Gas leakage |
| Acid-carbonate reaction | Particle size | Carbon dioxide-production rate | Defining surface area |
| Food-dye fading | Temperature | Absorbance change per unit time | Instrument calibration |
A focused question might ask: How does temperature from 293 K to 313 K affect the rate constant of a teacher-approved iodine clock reaction under constant reactant concentrations? If the evidence supports it, temperature data can allow an Arrhenius analysis. The RevisionDojo Chemistry IA kinetics guide provides further measurement options.
Acids, bases, and analytical chemistry
Titrations are accessible in many school laboratories and can generate precise data. The challenge is to investigate a chemical relationship rather than merely rank products.
Suitable directions include:
- storage temperature and titratable acidity of juice
- antacid composition and neutralizing capacity through back titration
- weak-acid concentration and percentage ionization
- temperature and an experimentally determined acid dissociation constant
A brand comparison becomes stronger when it calculates a meaningful quantity, such as moles of acid neutralized per gram. Sample preparation, endpoint determination, and concentration should be standardized.
Energetics and calorimetry
Neutralization and dissolution calorimetry are generally more controllable than open-flame combustion. Variables may include concentration, ionic compound identity, initial temperature, or insulation thickness.
For example: How does reactant concentration affect the experimental molar enthalpy of neutralization between hydrochloric acid and sodium hydroxide when total volume and mole ratio are controlled? This supports discussion of heat loss, heat-capacity assumptions, probe resolution, and extrapolation.
Combustion studies may be rejected because of flames, incomplete combustion, soot, volatile fuels, and substantial heat loss. The RevisionDojo energetics topic guide suggests more controllable alternatives.
Electrochemistry and corrosion
Electrochemistry combines accessible measurements with substantial theory. Possible relationships include electrolyte concentration and cell potential, temperature and cell potential, applied current and deposited copper mass, or sodium chloride concentration and iron corrosion rate.
Electrode preparation, immersion depth, temperature, salt-bridge construction, and measurement time can influence results. A strong proposal explains how each will be standardized. See the RevisionDojo electrochemistry IA guide for suitable controls and measurements.
Colorimetry, adsorption, and equilibrium
Colorimetry converts visible changes into quantitative concentration data. Food dyes are often useful model substances, provided the investigation examines chemistry rather than simply asking which household material removes the most color.
Potential questions include:
- activated-carbon mass and equilibrium dye concentration
- contact time or pH and dye adsorption capacity
- ethanol-water composition and food-coloring extraction
- storage temperature and vitamin C concentration
- temperature and the solubility of a selected salt
- temperature or pH and aspirin hydrolysis
A calibration curve adds analytical depth, but measurements must remain within the instrument's reliable range. Students should also distinguish adsorption, which occurs at a surface, from absorption, which involves entry into a material's bulk.
Organic investigations require particular caution with volatile solvents, flammable liquids, concentrated catalysts, and heating. A supervisor may require microscale quantities, safer substitutions, or a different system. For more starting points, consult 50 practical IB Chemistry IA ideas, then adapt rather than copy an idea.
How to write a focused research question
A useful model is:
How does [quantified independent variable and range] affect [defined dependent variable with units] in [specific chemical system], as determined using [measurement method], while [important controls] are maintained?
Compare these versions:
- Weak: How does temperature affect reaction rate?
- Stronger: How does temperature from 293 K to 313 K affect the initial rate of oxygen production during catalyzed hydrogen peroxide decomposition, measured with a gas syringe under constant reactant volumes and catalyst concentration?
The stronger version identifies the variable, range, measurement, system, and method. Finalize the range only after a pilot confirms that the reaction is measurable, safe, and neither too fast nor too slow. Use the RevisionDojo Chemistry IA research-question guide as an approval checklist.
Why supervisors reject Chemistry IA ideas
Rejection usually concerns safety, feasibility, or the quality of obtainable evidence. It does not necessarily mean the broader chemical topic is unsuitable.
| Problem | Why it matters | Practical response |
|---|---|---|
| Hazardous procedure | Risk exceeds school controls | Reduce scale, concentration, or substitute reagents |
| Unavailable equipment | The output cannot be measured reliably | Redesign around existing apparatus |
| Broad question | No precise relationship is tested | Define one variable and one measured output |
| Qualitative result | Visual judgments limit analysis | Measure absorbance, pH, mass, voltage, or gas volume |
| Limited chemistry | The task becomes product testing | Identify a chemical model, equation, or mechanism |
| Change below instrument resolution | Noise may hide the trend | Pilot the method and adjust the range |
| Several variables change together | Causal conclusions become invalid | Standardize composition and preparation |
| Excessive duration | Repeats become impractical | Reduce scope or shorten the procedure |
Students may collaborate in small groups under current arrangements, but the official curriculum update states that each student must have a different independent or dependent variable and collect unique data. Each student submits an individual report.
Test the topic before committing
A pilot should establish whether the apparatus works, the response is measurable, the range produces variation, and sufficient repeats are possible. Before approval, ask:
- Can I explain the underlying chemistry?
- Does the measurement answer the question directly?
- Can I justify the range, intervals, and repeats?
- Which variables could distort the result?
- What measurement uncertainties will I record?
- Is accepted theory or literature available for comparison?
- Can the school manage every hazard and waste product?
Read the RevisionDojo Chemistry IA criteria guide during planning. It helps determine whether the topic supports all four criteria before substantial practical work begins.
Conclusion
The best IB Chemistry IA topics are focused, quantitative, safe, chemically meaningful, and realistic with available equipment. Pilot the method, complete an appropriate risk assessment, and choose a system that produces evidence you can analyze, interpret, and evaluate.
RevisionDojo's complete Chemistry IA guide can support planning, while the Chemistry IA Grader can help you review a draft against the criteria.
Sources and referenced URLs
- Official IB Chemistry subject brief
- IB Chemistry curriculum page
- Official IB Chemistry curriculum update
- ACS secondary-school laboratory safety guidelines
- RevisionDojo Chemistry IA topic ideas
- RevisionDojo Chemistry IA kinetics ideas
- RevisionDojo Chemistry IA energetics ideas
- RevisionDojo Chemistry IA electrochemistry ideas
- RevisionDojo Chemistry IA research-question guide
- RevisionDojo Chemistry IA criteria guide
- RevisionDojo complete Chemistry IA guide
- RevisionDojo Chemistry IA Grader