Marcy 10/29/2019 - Oozing Pumpkins and Lava Lamps
Experiment Leaders: Gaurav and Matt
During our visit in October, we talked with Marcy students about chemical reactions. During the introduction, we were all surprised to learn that the Statue of Liberty did not start out green! It’s made of brown copper, which turned green because of a chemical reaction.
Once the students learned about reactants and products, we also taught them about catalysts that help speed up chemical reactions. They learned that saliva contains an enzyme catalyst that helps us break down food when we eat.
After the introduction, we showed a demonstration of a chemical reaction. We added a catalyst and soap to hydrogen peroxide, all inside of a pumpkin, and watched as the hydrogen peroxide quickly broke up into water and oxygen oozing out of the pumpkin. The students were impressed by the amount of heat that the reaction put out.
Next, the student broke up into groups to make their own lava lamps. For this experiment, they added water and vegetable oil to a small jar. Then food coloring was added, which mixes into the water.. And finally, alka seltzer tablets were added. This caused colorful bubbles to float around the jar like a lava lamp!
Oil and water do not mix because they have different densities, therefore, the water sinks and the oil floats on top. When the alka seltzer tablet is added, carbon dioxide forms in the water and colorful bubbles of this gas float to the top of the jar, because the carbon dioxide is less dense than the oil. Once the bubbles pop, the color sinks back down to the bottom of the jar.
