2 Ways to Make an Erupting Volcano

This activity is taken from “Let’s Go Live with Maddie & Greg”, a live family science show on YouTube!

View the full episode this activity is taken from on YouTube

“We love this activity because it’s a classic science demo packed with messy, explosive fun!”

Materials you could use

Mentos Volcano: A bottle of diet Coke

Mentos Volcano: A pack of Mentos mints

Mentos Volcano: Drill (to make a hole in the bottle cap)

Mentos Volcano: Paperclip

Mentos Volcano: Plasticine/papier-mâché model of a volcano (optional)

Bicarb Volcano: Small plastic bottle

Bicarb Volcano: ½ tablespoon Bicarbonate of Soda

Bicarb Volcano: 100 ml Vinegar

Bicarb Volcano: Red Food Colouring

Bicarb Volcano: Papier Mache for volcano

Bicarb Volcano: Washing up liquid (small squeeze)

Method

Safety first!

This one will need adult supervision and should be done outside as it will make a mess!

Mentos and Diet Coke Volcano

1. Make a hollow model volcano using whatever recycling / Plasticine / papier-mâché you have at home (See video for M&Gs version). Make sure it is big enough to cover a large Diet Coke bottle.

2. Get an adult to pierce or drill a hole in the lid of the Diet Coke bottle.

3. Carefully make holes in some mentos with a straighened paperclip, then thread them onto it, bending the paperclip under them so they don't fall off.

4. Thread the lid onto the paperclip above the mentos and keep hold of that end.

5. Still keeping hold of the end of the paperclip screw the lid onto the Diet Coke bottle making sure that the Mentos aren't touching the Diet Coke.

6. Make sure everyone has stepped back and, at arms length, push the paperclip end down through the cap so it falls - with the mentos - into the Diet Coke! Run away!

Diet coke is mostly made of sugar, flavoring, water, and a gas called carbon dioxide (CO₂) that makes the drink fizzy. If we shake a bottle of fizzy drink, some bubbles of carbon dioxide might escape the liquid and will stick to the sides of the plastic bottle. When the bottle is opened, these bubbles will quickly rise to the top pushing the liquid out of the way. This is why fizzy drinks sometimes spray when we open them!

If you feel a Mento mint, the sugary shell is a little rough, that’s because it has thousands of tiny pits all over the surface. These tiny pits make the perfect place for carbon dioxide bubbles to form. As soon as the Mentos hit the diet coke they sink to the bottom of the bottle because they are heavy, but very quickly little bubbles of carbon dioxide form all over the surfaces of the sweets making them rise to the surface, pushing the liquid out of the way and up through the nozzle of the bottle!

Bicarb Volcano

1. Make small model volcano with plastic bottle in middle to represent magma chamber.

2. Put the vinegar, food colouring & washing up liquid into the bottle.

3. Add bicarb to the bottle.

4. Watch it erupt!

When we mix the vinegar (an acid) with the bicarbonate of soda (an alkali), a chemical reaction happens which releases bubbles of carbon dioxide gas from the bicarbonate of soda. The washing-up liquid traps those bubbles so it flows over the ‘volcano’ like real lava!