Relight my fire!


12 October 2020

Mr Youde’s Year 7 class have been learning all about the decomposition of hydrogen peroxide (H2O2) with an experiment showing it decomposing into water and oxygen gas in the form of foam.

Under normal conditions the reaction takes place very slowly, therefore a catalyst, in this case iodide ion from potassium iodide, was added to speed up the process, which resulted in the rapid formation of foam while remaining chemically unchanged in the reaction process.

The potassium iodide quickly broke apart the oxygen from the hydrogen peroxide, and because it did this very fast, it created lots and lots of bubbles. The glass container also got warm, so this experiment created a reaction called an Exothermic Reaction – meaning it not only created foam, but it also created heat!

“Fortunately for my class the foam produced is just water, soap, and oxygen and so can be easily cleaned up with a sponge,” said a smiling Mr Youde.


Kallum and Jake test for oxygen with a glowing splint - it will relight to prove the presence of oxygen