Rainbow In A Jar Science Experiment

Create Your Own Liquid Rainbow With This Density Experiment For Kids

What if you could create your own rainbow in a jar with your little one? Rainbows are beautiful things, aren’t they? Did you know a rainbow is formed because of reflection, refraction and dispersion of sunlight through raindrops? Now imagine if you could make a beautiful liquid rainbow in your kitchen! It would be a fun science experiment, wouldn’t it?  The rainbow in a jar experiment is a great way to introduce your child to concepts like volume, density and viscosity. 

Why You Should Do The Rainbow In A Jar Science Experiment

When kids learn these science concepts in school, it often remains an abstract concept for little kids. But when you teach the same concept through a science experiment at home, it becomes easier for them to understand. Science experiments for kids at home are fun activities, which help kids connect the textbook knowledge to real-life applications. The rainbow in a jar science experiment is one such activity that will leave your kids in awe. 

Additionally, it’ll help them understand concepts like measurements and the density and viscosity of different liquids. The rainbow in a jar experiment also teaches kids about colors and how mixing two or more colors produces a different color.

Here is a step-by-step guide to performing this simple experiment in your home.

Things You Need To Make A Rainbow In A Jar 

Here is a list of things you’ll need to perform the rainbow in a jar experiment. All of these are simple and inexpensive things that you can find in your kitchen or pantry.

  • A clear, tall glass jar
  • 1/4 cup Honey
  • 1/4 cup green Dish Soap
  • 1/4 cup Water
  • 1/4 cup Olive Oil
  • 1/4 cup Rubbing Alcohol
  • Red, blue and green food coloring
  • Jars or bowls for mixing and pouring, and
  • Spoons for mixing

Steps To Set-Up The Rainbow In A Jar Experiment

Ready to make your own rainbow? Here are the step-by-step instructions to create your own rainbow in a jar. 

  • Step 1: Place the ¼ cup honey in a bowl and add one drop of red food coloring and one drop of blue food coloring to it. Stir well to combine or until the honey becomes purple. Pour purple honey into the tall glass jar.
  • Step 2: Then, measure and pour ¼ cup of green dish soap into the tall glass jar, over the purple honey.
  • Step 3: Next, add a few drops of green food coloring to ¼ cup of water in a bowl and mix well to combine. Now, tilt the tall glass jar slightly and carefully pour the green water into the jar. You need to ensure that the water runs down the side of the jar slowly.
  • Step 4: Wait for a few minutes and then pour ¼ cup of olive oil into the tall glass jar. Again, tilt the jar slightly and pour the liquid slowly so that it runs down the side of the jar. This ensures that the colors don’t mix and ruin the rainbow.
  • Step 5:  Finally, mix one drop of red food coloring with ¼ cup of rubbing alcohol in a bowl. Stir well to combine and then pour the liquid carefully into the tall glass jar. You need to ensure that you tilt the jar each time when you pour the liquid into the jar to avoid mixing all those beautiful colors. And voila! Your beautiful rainbow in a jar is ready! 

Note: If you find it difficult to tilt the jar and pour the liquid, you can use a dropper. Fill the jar using a dropper, but ensure that you pour the liquid slowly along the sides of the jar. And be very careful not to shake the jar at any point, or the colors will mix. This will ensure a beautiful rainbow with distinct colors in the jar.

Conduct An Interactive Session With Your Kid After The Rainbow In The Jar Experiment

The colorful rainbow formed in the jar will leave your child in awe for several hours. Help them understand the science behind the rainbow in a jar experiment by asking them a few leading questions. Give them a few hints and see if they can arrive at the answer on their own. Then explain the concept of volume and the different density and viscosity of different liquids to them.

Here is a list of questions to help you get started:

  • Why do you think the colors stay intact in the jar without getting mixed?
  • Why didn’t the liquids mix in the jar?
  • Did you learn anything new from the rainbow in a jar experiment?

The Science Behind The Rainbow In A Jar Experiment

  • How did the liquids in the jar stay intact without mixing with each other? The reason why the colored liquids stayed on top of each other without mixing is density! Each of the different liquids that we added into the jar has different densities. Olive oil and rubbing alcohol are liquids with lighter density, while honey, dish soap and water have higher density. This is why the colored liquids stayed in the jar without mixing and thereby forming a beautiful rainbow in a jar.
  • What is density? “Density is the measure of mass per volume”. The heavier density of a substance, the more likely it is to sink. And liquids with lighter densities will float on top. 

Other Ways To Do The Rainbow Science Experiment?

Here are some other ways you can perform the rainbow in a glass experiment.

Rainbow Jar Science Project Using Colored Rice

Try the rainbow in a jar with different colored rice. Use red, blue, green, yellow and orange colored rice. Measure ½ cup of each colored rice and pour it into the jar. Then, see if it mixes. 

Sugar syrup rainbow

Try performing the density experiment for kids with water and sugar. Fill four glasses with ¼ cup of water and add red, blue, yellow and green food coloring. Then add 2 tablespoons of sugar to the red liquid and 4 tablespoons of sugar to the blue liquid. 

Add 6 tablespoons of sugar to the yellow liquid and finally, add 8 tablespoons of sugar to the green liquid. Mix till the sugar dissolves. Carefully pour each of the colored liquids into a clear mason jar using a dropper, in the order green, yellow, red and blue. You can make a rainbow in a jar using this method too. 

  • Why don’t the different waters mix in the jar? Adding an increasing amount of sugar to the same amount of liquid creates several liquids with different densities. So, when they’re poured into the jar, the liquids don’t mix and leave you with a stunning rainbow in the jar.