Mouse Toothpaste


During an exothermic reaction, HEAT is created during the reaction.

 See what happens when hydrogen peroxide is helped along its chemical reaction journey by yeast to produce some big foam fun.


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*Note: These chemicals can be purchased locally at stores such as Walmart/Target.



In the glass beaker, use stirring rod to mix yeast with 50 mL of warm water and set aside for 5 minutes.


Pour hydrogen peroxide in Erlenmeyer flask and add food coloring (optional). 


In small beaker, measure dishwashing soap and pour into Erlenmeyer flask.


Use the thermometer to measure the temperature of the Erlenmeyer flask.


Once yeast has set for 5 minutes, pour it into the Erlenmeyer flask and observe the chemical reaction.  The resulting foam is safe to touch, see if it is hot.


Take a measurement from in the Erlenmeyer flask and note the temperature difference from your first reading.


The Science Behind the Reaction

This exothermic reaction results from a breakdown of the hydrogen peroxide into oxygen and hydrogen.  The yeast speeds up the chemical reaction, and well, the soap is just there to capture those oxygen molecules and make a cool foam.  The resulting chemical in the Erlenmeyer flask is hot as breakdown of the hydrogen peroxide is an exothermic (heat producing) chemical reaction.

Keep Experimenting

For an even bigger explosion, purchase "20-volume hydrogen peroxide" from the beauty store (or on Amazon).  Complete the same experiment above, replacing the 3% hydrogen peroxide with the 20-volum hydrogen peroxide.