Do your kids also love science experiments?
Well, you’ve come to the right place! This liquid rainbow experiment is so much fun with its bright colors. You’ll only need a few supplies that you probably already have at home.
Furthermore, this experiment is quite quick to do and with no prep time. So, keep on reading to see what you’ll need and how to do it.
This page is about a science experiment activity for kids and contains affiliate links. If you use these links to buy something I may earn a small commission but with no additional cost to you.
Materials, you'll need to make a liquid rainbow experiment
You will only need very few inexpensive materials to do this experiment:
- corn syrup
- blue dish soap
- water
- vegetable oil
- rubbing alcohol (denatured ethanol)
- liquid food dye (You’ll need green, red and purple. If you don’t have purple you can mix it with blue and red food coloring)
- glass vase or other tall see-through container for your liquid rainbow experiment
How to do the liquid rainbow experiment
The experiment is pretty simple to set up. Just make sure you always tilt your vase a little and pour the liquid slowly down the inside of your vase (see picture).
- Pour 1/2 cup corn syrup into your vase
- Add a few drops of purple food coloring to the corn syrup and stir (if you don’t have purple food dye then mix red and blue) – This is the PURPLE LAYER
- Tilt your vase and carefully pour 1/2 cup of blue dish soap into the vase – This is the BLUE LAYER
- Add a few drops of green food dye to 1/2 cup of water and pour carefully into the vase (tilt vase!) – This is the green layer
- Add 1/2 cup of vegetable oil to the vase (tilt the vase!) – This is the YELLOW LAYER
- Mix a few drops of red food dye with 1/2 cup of rubbing alcohol and pour carefully into the vase (tilt the vase!) – This is the red top layer
Science behind it the liquid rainbow experiment
There are two reasons why this layering of multiple liquid is possible.
First, liquids can have different densities and based on that have a different weight. The heavier liquid will sink to the bottom.
In this experiment the corn syrup is much denser than the dish soap and therefore stays at the bottom. The water on the other hand is less dense and therefore lighter than the dish soap. Consequently, the green water “floats” on top of the dish soap.
Secondly, some liquids simply don’t mix. Oil and water don’t mix as you probably know. For that reason, the yellow vegetable oil stays on top of the green water layer. Similarly, the red rubbing alcohol does not mix with the oil and floats on top of it.
Looking for more awesome science experiments?
I hope your kids will find this liquid rainbow experiment as astonishing as my kids did. Science is so much fun and it’s great if we can get our kids to see that at a young age already!
Please, check out my other posts about experiments and also look into some of my play ideas for kids.
