Elephant Toothpaste

This experiment can be done totally with things around the house, and is a great example of a batch reaction! All you need is a bottle, funnel, hydrogen peroxide, dish soap, water, instant yeast, food coloring, a tray to contain the mess, and eye protection (of course!). 

Start by mixing a half cup of hydrogen peroxide and a quarter cup of liquid dish soap in a water bottle. Add some food coloring to make the toothpaste look even cooler! Then mix a tablespoon of instant yeast with 3 cups of warm water in another container. Once you have your eye protection on and setup a tray to contain the experiment, add the yeast mixture into the bottle and watch your toothpaste grow! 

This reaction is possible thanks to the catalytic effects of yeast. The yeast contains an enzyme that breaks down hydrogen peroxide in two smaller molecules, water and carbon dioxide. The oxygen is a gas, which gets trapped in the soap and forms lots of bubbles, making elephant toothpaste!

This is very similar to how yeast is used to make bread rise. When yeast is mixed into dough and heated in an oven, it feeds on sugars in the dough and produces carbon dioxide as a byproduct (just like you do when you breathe). The carbon dioxide gets trapped in the dough and forms bubbles, making the fluffy bread that people use from sandwiches to cakes!