Elephant's toothpaste

Session focus: Exploring rates of reaction through varying concentrations of Hydrogen Peroxide

Starting the Science Pioneers program with a blast, our first class featured none other than the classic Elephant’s Toothpaste experiment in which a fountain of foam shoots up into the air upon mixing two chemical reagents. Today, the students explored one determinant of rates of the reaction: concentration. They experimented on how varying concentrations of Hydrogen Peroxide had an effect on the speed and force of the foam.

Lesson materials:

Chemicals:

• Hydrogen peroxide 

• (conc. 3%, 6%, 12%,30%) 250ml x1 of each conc.

• Dish Soap

• Potassium Iodide 250ml x1

• Food coloring (green, blue, red)

Equipment:

• Large plastic box x5

• 250ml Conical Flasks x10

• Gloves x5 pairs

• Funnel x5

• Timer x5

Lesson Plan:

• Hand out worksheet to students https://docs.google.com/document/d/1aloxhminVKw-cwy72PMf5-Hw7Kst3AvM6j-xrZ4NlTE/edit 

• Students carry out own experiments at desks using different concentrations of Hydrogen Peroxide, members may help with lab equipment

• 1st round - low conc.

• 2nd round - medium conc.

• 3rd round - high conc.