Combining baking soda and vinegar is a kid favorite for making volcanoes. Are there other ingredients that can make a similar eruption? We tried making a pop rocks volcano to find out.
Make a Pop Rocks Volcano
What You’ll Need:
- A volcano (or at least a container)
- Pop rocks
- Dish soap
- Food coloring (optional)
First, you’ll want to create the volcano. We placed a cup on top of an old plate. Then, Aiden covered it with brown play dough. I used The Imagination Tree’s no cook play dough recipe. Instead of the cup, you could use the soda bottle as your container and cover it with play dough. If you don’t want to use play dough, you could make a simple tape volcano.
In your volcano, add a squirt of dish soap and some red food coloring. Then, pour in the soda. You can fill the container most of the way full (or experiment and start with three-quarters). Add a handful of pop rocks to the volcano.
You’ll start to hear them pop and the volcano will bubble up and fizz.
We found the reaction to be quite slow, so we added some more soda to speed it up a bit.
The Science Behind It
Pop rocks contain pressurized carbon dioxide covered with a candy coating. When the candy coating begins to dissolve, the carbon dioxide gas is released. (It breaks through the now thin candy shell.) That’s when you hear the popping sound. The candy coating dissolves in your mouth or in other liquids like water and soda. Soda contains dissolved carbon dioxide. Adding the pop rocks to the soda provides a surface for carbon dioxide bubbles to collect. The bubbles head to the surface and push their way out of the container causing the eruption. The addition of soap to the pop rocks volcano makes the eruption more frothy.
Turn This Into an Experiment
To make this an experiment, we simply need to change something. Try one of the following ideas:
- What happens if you put the pop rocks in first and then add the soda?
- Use water instead of soda. How do the eruptions compare? (We tried this. We heard lots of popping but there was no eruption.)
- Will different brands of soda affect the reaction?
- Does changing the size of the container’s opening change the eruption? We used a cup with a wide opening. What would have happened if we used a soda bottle with a narrow opening?
- Try changing the temperature of the soda.
- What else could we change about the pop rocks volcano?
More Fizzing Science
- See 10 more ways to make a volcano.
- Use the baking soda and vinegar reaction to make bubbles.
- Check out these 20 baking soda science ideas for even more baking soda and vinegar fun!
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This post was originally published on September 8, 2016.