Disclaimer - This information is not directly from IB, but advice from myself of things I have learnt teaching IB Chemistry.
Vitamin C content of ‘superfoods’ – Use redox titration to find out if superfoods like kale and broccoli contain more vitamin C than oranges and peppers
The calcium content of various substances – Use EDTA titration to determine the amount of calcium in substances including tap water, milk, eggshell and limestone.
Finding the relative molecular mass of washing soda by titration – Use acid-base titration to find out how many waters of crystallisation there are in washing soda
Investigating caffeine content – Using colorimetry to assess whether different teas (white, black and green) contain different amounts of caffeine
Identifying a hydrated salt – Use thermal decomposition to accurately determine the formula of an unknown metal salt
Calculating the percentage iron in vitamin tablets – Determine the percentage iron in various tablets by redox titration with MnO4- to see if expensive brand iron tablets contain more iron than cheaper supermarket ones.
The concentration of ethanoic acid in vinegar – Measure the amount of ethanoic acid present in various brands by titrating against sodium hydroxide to see if the concentration of ethanoic acid in different types of vinegar varies.
The amount of aspirin in a tablet – Determine the amount of aspirin in various tablets by back titration with sodium hydroxide and hydrochloric acid to check whether the aspirin content of different tablet brands varies.
How many moles of chalk? – Work out how many moles of chalk it takes to write your favourite poem by accurately weighing pieces of papers with chalk letter written on, then using letter frequency to calculate the total mass needed
Experiments with hydrogels – Measure water absorption per unit time for fixed masses of hydrogel from different nappies to see whether the hydrogels in more expensive brand nappies are more effective at absorbing water.
Investigating the Dissolved Oxygen Content (DOC) of river water – Use the Winkler ‘double redox’ method was used (Mn(II) to Mn(III), iodide/iodine) to find out if the DOC of your local rive is sufficient to sustain aquatic life
Determining how dissolved oxygen content (DOC) in water is affected by salt and temperature – Measure dissolved oxygen content in water containing varying amounts of magnesium chloride using a Vernier probe and Winkler method to see how DOC is affected by salt balance and water temperature
Investigating a rust remover – Use redox titration to compare the acid content of different brands of commercial rust remover
Investigating fluorescence – Investigate the fluorescence of chlorophyll and other biological pigments using spectrophotometry
Factors that affect the light absorbed by a transition metal complex – Measure absorbance of light for different concentrations of copper (II) sulphate solution using colorimetry.
Microscale reactions of chlorine – Use microscale chemistry to prepare chlorine and investigate its reactions with halides and metals
Thermal stability of carbonates – Use thermal decomposition to investigate the relationship between charge density and the thermal stability of different carbonates
Finding and comparing the enthalpy change of combustion of alcohols – Using calorimetry to check if alcohols with more carbons in them have a higher enthalpy of combustion
Determining enthalpy of neutralisation – Use calorimetry to see if the enthalpy of neutralisation for different acids and alkalis is always around -55 kJ mol-1
Using Hess’s Law – Measure the enthalpy changes for the dissolving an anhydrous and hydrated salt (such as copper sulfate or cobalt chloride) in order to work out the enthalpy for the hydration process.
Using Hess law to calculate enthalpy change – Measure the enthalpy changes for the reaction of magnesium and magnesium oxide with hydrochloric acid, then use Hess’s Law to work out the enthalpy of formation
Investigating cooling pack chemistry – Use calorimetry to determine which endothermic reactions would be suitable to produce cooling packs based on cost and safety
Which conditions denature lipases? – Investigate the effects of UV light, temperature and pH on the rate of fat digestion by lipase to see which factor has the greatest effect.
Investigating the hydrolysis of aspirin – The effects of pH and temperature on the rate of aspirin hydrolysis
Determining activation energy – Measure the rate of a chemical reaction at different temperatures and use an Arrhenius plot to calculate its activation energy
Investigating the rate of reaction between sodium thiosulfate and hydrochloric acid – Use the vanishing cross method to investigate the rate of reaction between sodium thiosulfate and hydrochloric acid in order to determine the rate equation
Catalysis of hydrogen peroxide decomposition – Monitor the rate of reaction by measuring the volume of oxygen evolve to see which catalyst breaks down hydrogen peroxide faster, manganese dioxide, liver, or potassium permanganate
Finding a good catalyst – Use different acids to see which is most effective at catalysing the esterification of propanoic acid. Measure Kc by determining the amount of unreacted propanoic acid present using a titration to show it is not affected by a catalyst
Investigating the qualitative effect of temperature on equilibrium – Solutions containing cobalt complexes are heated and cooled and colour changes are observed to see whether the reaction is exo- or endothermic
Determining an equilibrium constant – Use gas chromatography to measure the concentration of ester in an esterification reaction mixture over time and hence determine Kc for the reaction between propanoic acid and ethanol?
Acids and bases
The effects of pH and substrate concentration on enzyme activity – Monitor the rate at which amylase breaks down starch into maltose at various concentrations of starch and at various pH values to find the optimum for the enzyme
The efficiency of indigestion remedies – Measure the time taken to neutralise a fixed volume of 1M hydrochloric acid (as a model for stomach acid) for a variety of indigestion remedies (tablets, powdered tablets and liquids) to see whether liquid forms of indigestion remedies better than the tablet versions.
Determining K and the Gibbs free energy for a redox reaction between iron and zinc. – Measure the cell potential for a cell containing iron and zinc half cells at various temperature to see if the reaction between iron(II) and zinc metal spontaneous at 298K
The dependence of electrode potentials on concentration – Use a voltmeter to study the relative reduction potential of various metals and the concentration dependence of voltage in concentration cells.
Microscale electrolysis to investigate bubble overpotential – Use a microscale Hoffman apparatus to investigate the effects of voltage and bubble overpotential on the electrolysis of sodium chloride
Factors effecting the stability of unsaturated fats – Investigate how light and temperature effect the stability of common vegetable oils by measuring their iodine numbers
Synthesis of a sweetener from paracetamol – Is it economically feasible to synthesise the sweetener Dulcin from paracetamol?
More IA ideas
Investigate chemical equilibria (determine Kc for a reaction)
Investigate a weak acid-strong base titration (determine the Ka of a weak acid).
Investigate the enthalpy change of a redox reaction.
Investigate an aspect of a simple voltaic cell.
Investigate the Ideal Gas Laws using a data logger.
Determine the amount of copper in coins using colorimetric analysis.
Analysis of seaweed (seaweed is a good source of Br and I).
Investigate the amount of CaCO3 in brown and white eggshells.
Compare the percentage of vitamin C in various brands of juice.
Investigate the hardness of water from different local sources.
Investigate the speed of neutralisation of antacids from different sources.
Investigate the kinetics of the bromine clock reaction to determine the order of reaction.
Investigate factors affecting electroplating.
Investigate factors affecting electrolysis.
Investigate the % of chlorine in different bleaches or swimming pool water on different days.
Investigate the enthalpy of neutralisation of different acid / base concentrations.
Determine the activation energy of iodine-clock reaction under different temperature conditions.
Investigate the effect of pH on the rate of rusting.
Calculate the Kw for water at different temperatures by measuring its pH.
Investigate factors determining heat of combustion in alcohols.
Investigate the level of unsaturation in different oil brands.
Investigate the pH of soil when treated in different ways.
Prepare and test of buffer solutions when exposed to different pH conditions.
Investigate the effects of heterogeneous catalysis on the activation energy of a reaction.
Investigate how the hardness of water affects the solubility of salts.
Investigate whether oxidation of tea / coffee changes its pH.
Investigate the effect of soil pH on the chlorophyll content in plant leaves.
Determine the enthalpy change of the thermal decomposition of sodium hydrogen carbonate.
Determine the percentage of iron in an iron compound or a food stuff by a redox titration.
Determine the solubility of an ionic salt in water by plotting a solubility curve and compare the solubility with its literature value.
Investigate the effect of the length a salt bridge has on the dipped voltage produced by a voltaic cell.
Investigate a factor influencing retention in paper chromatography of amino acids.
Determine the calcium and/or magnesium content of milk by EDTA titrations.
Determine the concentration of biodiesel produced from fruits using calorimetry.
Investigate the energy densities of fuels versus the bond strength (using a database).
Measure the concentration of zinc ions in a dietary supplement.
Investigate variables affecting water absorption polymers.
Investigate the rate of evaporation of a liquid with respect to its temperature.
Investigate the effect of different sacrificial metals on the rusting of iron.
Investigate the rate of adsorption of organic acids on charcoal.
Investigate the factors affecting the colours of transition metal compounds (through the use of a colorimter).
Investigate the factors affecting the rate of reaction between iodine and propanone.
Investigate an equilibrium position and Le Chatelier’s principle spectroscopically.
Investigate the catalytic abilities of different transition and metal oxides.
Investigate the solubility of salts (Ksp values).
Investigate the equivalence point of weak / strong acids and weak / strong bases.
Investigate the esterification of soaps.
Investigate the effect of different ionic salts on the freezing point depression of water.
1) Decide on an investigation topic which interests you and in which you are confident in your subject knowledge. By picking your best topic, you will be able to showcase clear chemistry throughout your report.
2) Once you have decided on the experiment, check whether it can be linked to a real world situation. For example, if you choose preparing esters as your favourite topic, then you can think about how to improve the essence of a particular ester in less alcohol and carboxylic acid or how the essence of an ester changes when you increase or decrease the concentration of alcohol or carboxylic acid or both.
3) Make sure your research question is clear and focused. Don’t write a vague question which no one can understand other than you.
4) Set a clear base with proper background information. Read through the content and make sure you bring only relevant points into the background information. Don’t write about organic chemistry, classification of alcohols, types of acids etc. If possible use any relevant stoichiometric equations and diagrams. Don’t confirm or decide your conclusion here. You will not impress your teacher or moderator by saying that you expect this result in the background information because when you know the result you don’t need to do the experiment to prove it is right. Finally, don’t cut and paste information from other sources to impress your teacher or moderator. They know very well what has been written by you and what has been plagiarised.
5) Selecting variables is a key in any investigation. Make sure you get a minimum of two independent variables which are measurable, and justify each and every variable if possible.
6) List apparatus and material requirements separately and make sure you clearly show the quantity and uncertainty of each one where appropriate. If there is available space, you can also give justifications of your choices in picking apparatus.
7) If someone wants to perform your experiment, they must be able to do so by reading your methodology. Keep it generalised. Don’t say, “I filled the burette with 50ml of ethanoic acid”.
8) No investigation occurs without safety precautions and ethical considerations, so make sure you spend some of your writing on the risk assessment.
9) Distinguish your data collection table for qualitative (if only appropriate) and quantitative data. Make sure a title is given to every table and graph. Label the axis and check that the table is clear enough to understand. Data collection can easily convey to your teacher/moderator how much care you have taken in your investigation and how precise you are in every bit of data.
10) Show clear working of raw data. Process the data with appropriate graphs with error bars. Show the errors and, if appropriate, discuss the qualitative data. These factors will encourage the reader to read the conclusion.
11) The conclusion is the right place to refer back to your research question with the support of your processed data. Compare your experimental data with theoretical data. Link the difference with the error calculation. Justify why you got the difference in value by discussing your weaknesses and the difficulties you faced during the investigation. Don’t forget to say what went well. It is always important to point out your strengths along with any weaknesses.
12) Wrap up your IA by saying what you will improve if you get another chance in future to perform the same experiment.
13) Don’t forget to mention how you could extend this investigation. Would you like to do further research in future on the same topic? Can you consider linking your IA with any other branch of science? Show curiosity and eagerness in your write up about your topic. This will gain some points in personal engagement and communication.
14) Check the presentation of your work. Ask yourself if your presentation is communicating interesting facts with clear chemistry. Remember, printing in colour ink doesn’t make good communication or presentation. Conveying your content in a clear way is the best possible communication. Don’t forget to check whether you are within the word and page limit.
15) Finally, check whether you have referred to everything in a bibliography in alphabetical order. Academic honesty is one of the emblems of IBDP.