This is a lesson which meets specification points within the WJEC GCSE ‘The Sciences’ Double Award (2026) spec, specifically from Unit 2.3 Rate of Reaction (Chemistry).

The lesson begins with an introduction to the investigation. The rate of a chemical reaction can be increased by using a catalyst. A catalyst is a substance that speeds up a reaction without being used up during the process. Catalysts work by providing an alternative reaction pathway with a lower activation energy, allowing more successful collisions to occur between particles.

In this investigation, students will study the decomposition of hydrogen peroxide and investigate how the presence of a catalyst affects the rate of reaction. Manganese dioxide will be used as the catalyst, and the volume of oxygen gas produced will be measured using a gas syringe.

The reaction equation is: hydrogen peroxide → water + oxygen

Students will compare the reaction with and without the catalyst to determine how catalysts affect the rate of reaction.

The next couple of slides outline the equipment needed and the method list for this investigation. Students will then ‘Think > Pair > Share’ their ideas about a results table should look like. After a class discussion, the teacher can draw some example tables on the board so students have an idea about what they need to include for their results table.

After this, in pairs/groups students should have another discussion about the control variables and potential sources of error in the investigation. Some examples for each of these are included in the PowerPoint for the teacher to go through.

Now, students can complete the investigation, recording their results as they go. Once complete there are a set of analysis questions for them to answer, based upon the results they have collected.

All resources are included. Thanks for looking, if you have any questions please let me know at swyftresources@gmail.com and any feedback would be appreciated.