Fall is in the air, which means pumpkin season is finally here! If your kiddos love carving pumpkins and elephant toothpaste this experiment is a must. Follow the instructions below to create your own erupting pumpkin. We recommend children observe the experiment portion of this activity.
- 2 packets of active dry yeast (total 16 grams)
- 6 tbs of warm water
- 1 cup of 12% hydrogen peroxide (or volume 40 hair developer found at beauty supply stores)
- 2 tbs of dish soap
- food coloring
- carved pumpkin
- safety goggles
- plastic container or large cup (should fit into your pumpkin)
Start by carving a pumpkin or use a pumpkin that you have already carved. In this example, we cleaned the inside of the pumpkin and drilled 1/2 and 3/4 inch holes all around.
Next, pour 1 cup of hydrogen peroxide into a container. Add a few drops of food coloring and 2 tbs of dish soap. Mix well and insert into your pumpkin.
In a separate cup add 6 tbs of warm water and 2 packets of active dry yeast. Mix until the yeast has dissolved. Now for the fun part! Put on some safety goggles. Carefully pour the yeast mixture into the hydrogen peroxide and step back to see this amazing chemical reaction.
How Does it Work?
Normally hydrogen peroxide breaks down quite slowly into H2O and O2. In this experiment, yeast was used as a catalyst or a substance that increased the reaction rate. The yeast quickly broke down the hydrogen peroxide into water and oxygen gases and created oxygen gas bubbles. When the oxygen tried to escape it got trapped by the dish soap creating lots of bubbles, resembling toothpaste coming out of a tube!