Let’s do a… Volcano Experiment!

By Becky Holmes

This post is brought to you by the littler members of the science made simple crew (aka Zach, 5 and Lexi,3) sharing their half term science adventures.

Zach and Lexi on their walk.  Photo: science made simple (All rights Reserved)

Zach and Lexi on their walk. Photo: science made simple (All rights Reserved)

We made a model of a volcano complete with an eruption! This was a perfect activity to do anywhere, we even did it in our caravan in the rain.

You will need.

Ingredients. Photo: science made simple CC-BY-NC

Ingredients. Photo: science made simple (CC-BY-NC)

  • Container for reaction – The volcano we used is from the horrible science range but if you don’t have one of those you can make your own. You need a small bottle with a plastic screw on lid. The plastic lid will need a hole added. The hole should be about 2mm wide.
  • Bicarbonate of soda
  • Plate
  • Malt vinegar
  • Teaspoon
  • Collection of twigs stones and anything you can find.
  • Optional: Pretend people to decorate your volcano, preferably in a running away position.

1. Set the scene. In the kit was a plastic volcano that we placed in the centre of your scene, it included little cardboard people.

To set the scene we needed to collect lots of twigs and stones. We headed out in the rain, in our waterproofs, to collect whatever we could find. The kids absolutely loved doing this and we even found a snail shell, after checking it was empty we added it to our collection. Unbeknownst to us however, a slug also sneaked in!

Zach finds a stick.  Photo: science made simple (All Rights Reserved)

Zach finds a stick. Photo: science made simple (All Rights Reserved)

2. Prepare your work station. You need a flat surface. We put our scene on a plate and all the mess was contained but we wouldn’t recommend doing it on your best dining room table without a plastic cover down.

3. Create your volcano! This can be as elaborate as you like. You could even have a couple of volcanoes. We kept ours simple. It was at this point we located the slug, who we promptly rescued to a place of safety to later be released. We didn’t think he would like the vinegar eruption that was headed his way.

lay out your stuff

Lay out your bits of volcano. Photo: science made simple (CC-BY-NC)


4. Put on your safety specs

safety zach

Zach is very safety conscious! Photo: science made simple (All Rights Reserved)

The kit we had came with a pair of science safety specs modelled by Zach. He and my little girl loved wearing these, but it did heighten his expectations, i.e. he was disappointed when the volcano didn’t erupt all over his face! He didn’t see the need for the specs after seeing one eruption. This is the perfect place to explain how reactions can be different, and communicate how to safely do science, just in case. Next we will be showing him the alkaselter rocket demo we did back in April so he gets the explosion he was expecting.

5. Add the vinegar to the volcano, about 45ml is ideal but you can play around with the quantities.

tip in vinegar

Tipping in the vinegar- Photo: science made simple (All Rights Reserved)

tip in vinegar from above

Still tipping in the vinegar! Photo: science made simple (All Rights Reserved)


5. Measure out the sodium bicarbonate into your volcano. 1 teaspoon is about right. As soon as its’ gone in………..

6…..Quickly screw on the lid.

screw on lid

Screwing on the lid. Photo: science made simple (All Rights Reserved)

7. Sit back and watch.


Erupting volcano! Photo: science made simple (CC-BY-NC)


Why not use a home-made bottle for the volcano, try out differing amounts of ingredients to see what gets the best eruption or even add some food colouring to see if you can get it even more lava like.

Make it an experiment

The process described above is a demonstration. To turn it into an experiment, make predictions and repeat the experiment – e.g. does the volcano erupt better with more or less sodium bicarbonate?

Send us a photo!

We’d love to see pictures of your volcano in full eruption, please email to info@sciencemadesimple.co.uk, or tweet to @scimadesimple.

If you want to try a similar reaction to propel rockets check out here.

What happened?

The vinegar reacts with the bicarbonate of soda to produce a gas. The gas takes up a lot of space and finally builds up enough pressure to push out of the opening at the top of the volcano.

Great discussion points

  • what state of matter is the vinegar? 
  • what state of matter is the bicarbonate of soda?
  • does the same thing happen in a real volcano?
  • what causes a volcano to erupt?
  • where do we find vinegar?
  • would you want to be near a volcano if it’s about to erupt?
  • why is lava red?
  • do slugs like vinegar?


That’s it from our little SMSers until the summer holidays!


Zach and Lexi say goodbye.  Image: science made simple (CC-BY-NC)

Zach and Lexi say goodbye. Image: science made simple (CC-BY-NC)

Curriculum Links

Key Stage 2:

  • Asking relevant questions and using different types of scientific enquiries to answer them
  • Setting up simple practical enquiries, comparative and fair tests
  • Making systematic and careful observations
  • Identifying differences, similarities or changes related to simple scientific ideas and processes


sms group shot with props smallWe are science made simple, a social organisation which promotes science, maths and engineering in schools and to the public. You can find out more about what we do, book us live in action with one of our exciting shows, or sign up to our newsletter and find out what we’re up to!




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Posted in Activity, Geology, Primary
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