Fun at Home - Making Gas

balloon on plastic canister

An investigation into expanding gas.

Use household items in a simple exploration of solids, liquids and gasses. Although we are using common household items, I strongly recommend some safety goggles and protective or old clothing when mixing bicarbonate of soda and vinegar.

Time to do and skill level. 

10 to 20 minutes, longer if you attempt all the demonstrations.

Easy to Medium - Adult help is essential for some of these demonstrations.

Equipment List

hairdryer hand pump balloon and bicarbonate soda

You will need:

  • An adult helper
  • Safety goggles
  • Plastic bottle
  • Bicarbonate soda
  • Vinegar
  • Balloons
  • Scissors
  • Hairdryer
  • Sticky Tape 
  • Film canister or similar plastic container
  • Dissolvable energy tablet and water as alternative to bicarbonate of soda and vinegar


Before you begin – How many different types of solids, liquids and gasses can you or your adult helper think of? What is the difference between a solid a liquid and a gas and how do they behave?

Step 1 – Can you see gas? Some gases are very brightly coloured while others appear invisible to the human eye. The air which surrounds you is a mix of gasses; how do you know they are there if you can’t feel them and you can’t see them? Take a balloon and inflate it with a hand pump. As you force air into the balloon it stretches to allow the air to fill it.

balloon and hand pump  balloon and hand pump

Step 2 - Instead of inflating the balloon by forcing more into it you can change the state of the air by applying heat. Stretch the mouthpiece of a balloon over an empty plastic bottle or jar before asking your adult to gently warm the outside of jar with a hairdryer. If you tried the hot air balloon experiment already you might remember that the hairdryer heats or excites the air molecules causing them to move apart from each other You should observe the deflated balloon slowly expand; it won’t inflate beyond the way it looks in the photograph here. If you try and apply too much heat you will melt the plastic jar.

balloon on plastic jar   inflated balloon on plastic jar

Step 3 – Previously we made the gasses inside the bottle expand by heating it up. For this next demonstration you and your adult are going to create gasses by mixing a liquid and a solid and changing their state. Pour a tablespoon of vinegar into the plastic film canister, if you don’t have one then you can use a plastic bottle. Pour a teaspoon of bicarbonate soda into a balloon before stretching the mouthpiece of the balloon over the canister. Gently tip the contents of the balloon into the canister. As the bicarbonate of soda falls into the vinegar there are chemical reactions taking place one of which is the forming of a gas called carbon dioxide. If your adult doesn’t have bicarbonate of soda or vinegar at home the they could try water and an energy tablet designed to dissolve in water.

inflated balloon on plastic jar  balloon on plastic canister


Further observations and discussion points for adult helpers

What happens if you change the quantity of solids and liquids that you are combining, will it change the volume of gas that is created?

What would happen if you changed the temperature of the vinegar or water in your demonstration?

Does the surface temperature of the container or balloon change when you mix bicarbonate of soda with vinegar?

In step 3 the gas expanded and stretched the surface of the balloon. What would happen if the balloon couldn’t stretch to accommodate the gas?

This video demonstrates what happens when I replaced the balloon with an airtight plastic lid. I made sure I was wearing safety goggles when I did this.

Take a picture if it's safe to do so and share on Instagram hashtag #museumofthegreatsouthern or Facebook remembering to tag us.

This Fun at Home activity is presented by:

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