How to Make Fireworks in a Jar

My son, Onetime just loves doing experiments – especially if they bubble and fizz! Today’s chemistry activity takes about 5 minutes to set up and is well worth the time! This colourful, bubbly, streaming reaction reminds me of mini explosions and so I’ve named it Fireworks in a Jar!

Inspiration for Fireworks in a Jar

For some reason lately, Onetime and I have been talking a lot about gases and how they are often invisible.

In the bathtub, we talk about the bubbles of air, we have pointed out the carbon monoxide detector and discussed why it’s there, we have chatted about trees and plants and how they breathe in carbon dioxide and release oxygen for us to breathe.

Today’s activity is a fun demonstration of how gases can make things happen, even when we can’t see them.

It’s also a fun and easy experiment to do around any of the holidays that we celebrate with fireworks!

Fireworks Supplies

• A see through glass/plastic jar
• Baking soda
• Vinegar
• Cooking oil
• Food colouring (we used red for Canada Day “fireworks”, but you could use red and blue, or whatever colour you like)
• Water
• An ice cube tray

Fireworks Prep

1. Several hours before the activity, measure about 1 tsp of baking soda into 3 or 4 ice cube compartments on your tray.

2. Fill the remaining space with water and add 4 or 5 drops of food colouring (whatever colour you want) to each. Mix until most of the baking soda is dissolved. Freeze!

3. Pour white vinegar into the see through jar to a depth of approximately 1 inch. Now slowly add cooking oil to a depth of 2 inches.

If you want to use 2 colours, you can add food colouring to the vinegar before you add the oil.

This experiment can be done inside or out, but be sure to have a plate or tray under your jar in case the reaction overflows.

Creating the Fireworks

Before you start, you might want to ask your child what they think will happen when you drop the ice cubes into the jar. I told my son that this is called making a guess – or a “hypothesis.”

I was quite surprised when my son said he didn’t know what was going to happen even though we’ve done an awful lot of baking soda/vinegar experiments, but apparently we need to do some more! LOL

To start the reaction, have your child place the ice cubes, one at a time into the jar.

Onetime really enjoyed watching the reaction (and so did I!) As the ice cube drops down through the cooking oil, nothing happens until it hits the vinegar.

Then all of a sudden, you get cool spherical coloured bubbles of carbon dioxide (created when the baking soda and vinegar react) rising up through the oil!

Streamers of foaming fizz explode too – just like fireworks!

Our reaction continued for 3 to 4 minutes, and each time a new ice cube was added, it started again.

During the experiment, we talked about the reaction and how the carbon dioxide gas that was being released in the reaction is less dense than the liquids and is rising to try to escape.

Onetime wondered whether the gas had a smell – and so he took a quick sniff and discovered that carbon dioxide is invisible and odorless.

Lots of fun! Lots of learning! And lots of new vocabulary (reaction, gases, density, invisible, hypothesis).

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Enjoy some bubbly explosive fun!

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