IB Chemistry: How to Come Up with the Best Chemistry IA Ideas

Stuck on ideas for a good Chemistry experiment? Scroll down to see a list of our best Chemistry IA experiment recommendations that will secure you top marks in your internal assessment!

16 days ago   •   5 min read

By KIS academics
Photo by Vedrana Filipović / Unsplash

Chemistry is regarded as one of the hardest subjects in the IB. IB Chemistry requires students not only to be able to understand the content and perform calculations but also to conduct their own research and analysis. Many students miss out on easy marks on their assignments, ultimately being the difference between a 6 and a 7 for them.

Want a 7 in your Chemistry IA? Keep reading to unlock the secret!

Overview of the Chemistry Internal Assessment

Before brainstorming ideas, it’s essential that you familiarise yourself with the IA and its requirements. Your Chemistry IA should:

  • Align with a topic from the IB syllabus
  • Allow you to collect sufficient data in a feasible time frame
  • Have scientific papers on the same topic/area
  • Be ethical, safe, and manageable with the resources provided to you

The IA contributes to 20% of your overall grade, and for most people is the difference between a 6 and a 7. This still leaves most of your grade left to your exams.

Step 1: Brainstorming Areas of Interest

The first step of creating your IA research question is to have broad topics of interest to you. Remember these broad topics must align with the Chemistry syllabus. Once you have some ideas, do preliminary research to explore specific questions or problems within those areas. This research will allow you to identify areas where further exploration into topics could be valuable.

For example, say you are really interested in energetics and thermochemistry, and how this affects reactions. You should then:

  • Research how temperature impacts reactions
  • Find articles and studies that discuss the effect of temperature on reactions
  • Note the dependent and independent variables and the ultimate outcome of the experiment

Bonus Tip: Find an exemplar that has scored a 7 and is written on a similar topic to yours. This will not only give you ideas but set you on the right path!

Step 2: Refining Your Idea

You have successfully addressed several broad ideas. Now you must refine them. A good IA has a clear research question – and is one of the most important aspects your marker will look at. The topic you choose should also include reasons for conducting research. The more focused your topic, the easier it will be to design a method, collect meaningful data, and stay on track.

Continuing with the thermochemistry example, say you find a lot of research of the effect of temperature on Aspirin (acetylsalicylic acid):

  • You find out that increasing temperature affects the rate of hydrolysis
  • Clearly state your independent variable (temperature) and the dependent variable (rate of hydrolysis)
  • You should also find out why this research is applicable

You must then formulate an in-depth question that has these criteria:

  • What independent variable are you changing (and by how much)
  • What effect in the dependent variable are you collecting data on
  • What are the units of the data you are collecting and how you are measuring it
  • The time frame of the experiment
    • This is not always needed – discuss with your teachers if they think it is applicable or not.

A good IA question will sound something like this:

What is the effect of temperature of water (278, 283, 288, 293, and 298 Kelvin) on the rate of hydrolysis (calculated in AU s-1) of Acetylsalicylic acid measured by amount of 585nm (orange) wavelength light absorbed by 2-hyrobenzoic acid (product of hydrolysis of aspirin) and Iron (III) metal complex using PASCO Spectrometer (AU)?

This research question tells us (and the marker) immediately:

  • What independent is changing (temperature)
  • The effect on the dependent variable (rate of hydrolysis)
  • The units (AU s-1)

This research is also very applicable to real life. Aspirin is used to provide pain relief. A higher rate of hydrolysis means it diffuses into our blood quicker – providing faster relief.

The key to a good IA question ultimately lies in a specific dependent variable and independent variable, and whether it is providing useful information on a certain issue. 

The Best Chemistry IA Ideas

1.  Effect of Temperature on Rate of Reaction

  • DV: Rate of reaction (can be measured in various ways such as measuring the absorbance of a specific wavelength)
  • IV: Temperature (varied using a water bath at different temperatures, e.g., 10°C, 20°C, 30°C, 40°C, 50°C)
  • Experimental Setup: Create a water bath at different temperatures. Allow reactants to sit in the water bath until they are the same temperature. Perform the reaction and record the data.
  • Rationale: This experiment will investigate how temperature affects the kinetics of particles, which is crucial for understanding many processes.

2. Effect of Concentration on the Rate of Reaction

  • DV: Reaction rate (measured by the time taken for a visible change to occur).
  • IV: Concentration of one reactant (e.g., concentration of hydrochloric acid in a reaction with magnesium ribbon).
  • Experimental Setup: Vary the concentration of the acid while keeping other variables constant, and measure how long it takes for the magnesium to fully react.
  • Rationale: This experiment explores the relationship between reactant concentration and reaction rate, reinforcing the collision theory and the rate law.

3. Investigating the pH Effect on the Corrosion Rate of Iron

  • DV: Rate of corrosion (measured by the mass loss of the iron sample or rust formation over time).
  • IV: pH of the surrounding environment (using buffer solutions of varying pH levels).
  • Experimental Setup: Submerge iron nails in solutions with different pH levels (e.g., acidic, neutral, basic) and measure the mass change or amount of rust formed over time.
  • Rationale: This experiment helps understand how acidic or basic environments accelerate or slow down the corrosion of metals, a common issue in industrial applications.

4. Electrolysis of Saltwater: Effect of Voltage on Gas Production

  • DV: Volume of gas produced at the electrodes.
  • IV: Voltage applied to the electrolysis setup.
  • Experimental Setup: Set up an electrolysis experiment with salt water and vary the voltage supplied to the electrodes, measuring the volume of hydrogen and chlorine gas produced.
  • Rationale: Investigating the relationship between voltage and gas production during electrolysis gives insight into electrochemical processes and Faraday's laws of electrolysis.

5. Effect of Surface Area on the Rate of a Solid’s Reaction

  • DV: Reaction rate (measured by the volume of gas produced or the time taken for a solid to dissolve).
  • IV: Surface area of the solid (using different sizes of solid reactant, e.g., powdered, granulated, or a single piece).
  • Experimental Setup: Perform a reaction between a solid reactant (such as calcium carbonate) and an acid, and measure the gas released or time taken for the solid to dissolve based on its surface area.
  • Rationale: This experiment investigates how increased surface area enhances reaction rate by increasing the frequency of collisions, a key principle in chemical kinetics.

And that’s how you can come up with the best Chemistry IA Idea. This IA cannot be rushed, so take your time researching and planning to set yourself up for success.


Want more personalized study guidance to help drastically improve your marks? A private tutor can make the biggest difference!

Written by KIS Academics Tutor for IB and QCE, Sameer Baad. Sameer is currently studying for a Bachelor of Advanced Finance and Economics at the University of Queensland. You can view Sameer’s profile here and request him as a tutor.

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