Since we have been spending a lot of time at home lately, we have decided to do some experiments. This pop rock experiment is a fun way for kids to learn about chemical reactions and carbon dioxide gas.
Pop Rock Experiment
To complete this experiment, you will need:
- 600ml bottle/s of soft drink of your choice
- one packet (7g or 0.25oz) of pop rocks for each bottle
- one balloon for each bottle
- small funnel
- Scientific flip book or worksheets
After completing their worksheets including the hypothesis about what soft drink they thought would work the best, we started the experiment. We chose Fanta, Coke and Diet Coke – which is in the Vanilla Coke bottle.
Once you have the workspace set up with your bottles, you will need to add one packet of pop rocks to each balloon. To do this, we added a balloon to the end of the funnel and poured the packet into the top.
We did have to shake the funnel around a little to help all the pop rocks slide into the balloon.
Once all the pop rocks are in the balloon, remove it from the funnel and hold the top together with a peg so the pop rocks can’t fall out while you are filling the rest of the balloons.
When you are ready, carefully place the end of the balloon over the open bottle mouth without letting any of the pop rocks into the soft drink.
Now is the time to remove the pegs and lift the balloons over the top of the mouth of the bottle allowing the pop rocks to fall into the soft drink.
Watch the balloons inflate!
Surprisingly our best performer was the Diet Coke. The coke went a little better than the Fanta.
The Science Behind it
The pop rocks contain a small amount of pressurised carbon dioxide gas. This gas makes the popping sound that you hear when they first free from their shells. The soft drink also contains pressurised carbon dioxide gas. When the pressurised carbon dioxide gas from the pop rocks hits the soft drink, some carbon dioxide escapes but has no where in the bottle to go, so what does it do? It rises into the balloon.