Next time you finish a sandwich, don’t throw out that ziplock bag right away. Do this science experiment with sizzles and explosions that will certainly entice kids to learn about chemical reactions and the elasticity of plastics.
STEM concept: Chemical reactions, elasticity of plastics
Challenge: Medium
Messiness: High
Materials
• baking soda
• toilet paper
• 1/4 cup vinegar
• ziplock sandwich bags
Steps to follow
Safety reminder: Because this experiment promises to be messy, it is advisable to do the experiment outside. Make sure the kids are at a safe distance from the ziplock bag as it expands and explodes. Baking soda or vinegar getting into their eyes can be painful and irritating, so ensure that safety precautions are in place. Another option is to make kids wear goggles.
1. Pour the vinegar into the ziplock bag.
2. Wrap the baking soda with the toilet paper, creating little round pouches.
3. Put the baking soda pouches into the bag.
4. Quickly seal the bag.
5. Wait until the bag fills with air and pops.
The science behind the experiment
Baking soda is a base, and vinegar is an acid. When mixed together, they create an acid/base reaction that produces carbon dioxide, water, and sodium acetate. This reaction causes bubbles and fizz.
The carbon dioxide produced from the reaction cannot escape and is trapped inside the sealed bag. Since the ziplock bag is plastic, it will expand as the gas molecules fill the bag. When it reaches its limit and the bag cannot hold anymore CO2, it will pop.
