The Rainbow Jar Experiment

Sharing is caring!

Rainbow Jar

Density is the ratio of mass to volume. You can easily see how things with different densities will behave differently in liquids. Learning about density is fun and easy with this Rainbow Jar experiment. With a few simple ingredients that you probably have around your house, you can witness the magic of density. Before we begin, please take a moment to pin this post to your homeschool board.

Pinterest Pin Rainbow Jar Experiment

How does the rainbow in a jar experiment work?

This experiment explores density, density is the mass of a unit of volume in a material substance.

Isabella explains it wonderfully at the beginning of her video which is on our channel and linked below.

Isabella used two cups and a bunch of pom-poms. In one cup she had a lot of pom-poms in the other just a few. This demonstration helps her to explain density.

Here is how we explain it. Almost everything is made up of molecules, the pom-poms represent molecules. The more molecules your item has the denser it is (the less space there is between them).

We are working with liquids in this experiment, each liquid has a different density which explains why they stack up on top of each other. Each liquid creates its own layer based on its density.

Let’s get started conducting this experiment.

Supplies to Create the Rainbow Jar Experiment

What you will need:

Tall Clear Container (Mason Jar)


Light Corn Syrup,

Green Dish Soap or Blue Dish Soap,

Olive Oil,


Rubbing Alcohol,

Food Coloring,


Instructions for the Rainbow Jar Experiment

What to do:

  1. First, gather your ingredients including a clean clear container, we used a mason jar.
  2. Next, let’s start making our rainbow! The first layer to put in is honey make sure to pour it into the center of the container.
  3. Then, mixing some food coloring with light corn syrup, we used purple food coloring.
  4. After that, put in the dish soap, our dish soap is green but if you use blue that is fine too.
  5. Next, add in the water, the regular tap water we colored blue, again if you used blue soap then color your water green.
  6. Then, add in our olive oil, we put a pretty thick layer.
  7. Lastly, using a dropper add rubbing alcohol which we colored red (that is a great peek at how density works when you add the food coloring into the rubbing alcohol the food coloring sinks and sits at the bottom). We used a dropper and slid it into the jar on the sides to create a layer, if you shoot it in or if you pour it in you risk a chance of the alcohol picking up the color from the previous layers.

Check out The Rainbow Jar Experiment in action:

Pin this post for later

Pinterest Pin Rainbow Jar Experiment

Similar Posts

One Comment

Leave a Reply

Your email address will not be published. Required fields are marked *