Chemical Reactions

What happens when you mix up a little hydrogen peroxide, yeast, and dish soap? NHCS Story Scientists investigated this chemical reaction after hearing sections of the 2013 Newbery Award winning book The One and Only Ivan by Katherine Applegate.

Ivan is a silverback gorilla in captivity and is the main character in this story. Ivan has a good friend named Stella, who is an old but wise elephant. Both animals are on display in the Exit 8 Big Top Mall, a sad place for an animal to live. We read four short chapters about Stella, which told us a lot about her character and also showed us the author's style of writing. This book tells a quite compelling story about caged animals. It's a very quick read with short paragraphs and chapters. It's an excellent book for anyone who's interested in animals!

Then, for the experiment! Materials were distributed and safety glasses were donned.

Students placed a recycled bottle in the middle of the cake pan, then poured in hydrogen peroxide. Nothing happened. They added food coloring and the hydrogen peroxide took on the color. They added a squirt of dish soap. Nothing happened. 

Next they mixed yeast and water together in a small cup until the yeast dissolved. They carefully poured the yeast mixture into the container with the hydrogen peroxide. The yeast was the catalyst!

And here's what happened. 

See why it's called "elephant toothpaste"? Students noted that the mixture and the bottle both felt warm due to the reaction between the hydrogen peroxide and the yeast. In a second trial, we added a lot more dish soap, and the mixture took on a sudsy quality rather than the smooth one you see here. This was our last attempt - a show for some of the onlookers who were in other groups. We mixed red and blue food coloring, hoping for purple elephant toothpaste! It was more like lavender!

Here's the link to the experiment! 

Don't forget your safety glasses!