Make your volcano
You could use play dough or clay (this is a good one for using homemade play dough – you can find a recipe in our Fun with Kids section) or do the experiment in your sand pit. Make your volcano by building it up around a plastic cup or bottle on a tray. Use brown play dough or clay to make your volcano more realistic.
For each eruption:
1/2 cup water
1/4 cup vinegar
1/4 cup dish detergent
A few drops of red food colouring
2 tbsp sodium bicarbonate
Add the sodium bicarbonate to your container in the middle of your volcano.
Mix the water, vinegar, dish soap and food colouring in a jug.
Pour the liquid onto the sodium bicarbonate and wait for the eruption!
What happens?
When vinegar and baking soda are first mixed, the hydrogen ions in the vinegar react with the sodium and bicarbonate ions. The result of this initial reaction is two new chemicals: carbonic acid and sodium acetate. This creates the bubbles and foam you see when you mix the ingredients together.
You could even experiment with different amounts of vinegar to sodium bicarbonate and see which gives the most impressive eruption.
Another cool eruption can be made from dropping a roll of Mentos mints into a bottle of Diet Coke (the diet version seems to work the best).
Simply take the lid off the bottle of coke and drop in your roll of mints. Then move away really quickly! All the mints sink to the bottom and make a lot of bubbles that rise to the surface and push the diet coke out in a big whoosh!
