How to Build a Volcano

Volcanos release pressure.

Watching hot lava spew out of a volcano is fascinating. A fun science experiment is to build a volcano using household products. You can make a simple volcano by using a plastic bottle, vinegar and baking soda. A more elaborate display can be created by making a replica of a volcanic mountain out of a flour dough mixture or paper mache. A chemical reaction happens between the baking soda and the vinegar that produces carbon dioxide. Pressure builds inside of the bottle which makes gas bubbles (lava) flow out of the the top of the bottle. This experiment will take about 30 minutes to make. Adult supervision is recommended.

Things You'll Need

• Baking pan or large tray
• 6 cups flour
• 2 cups salt
• 4 tbsp. cooking oil
• Funnel
• 2 cups warm water
• 16 oz. plastic bottle
• 2 cups water
• 2 tbsp. baking soda
• 1/4 cup vinegar
• Few drops orange, green, brown food coloring
• Few drops of detergent

Instructions

1. Create a flour dough to build the volcanic mountain. Mix six cups of flour, two cups of salt, four tablespoons cooking oil and two cups of warm water together. Add green or brown food coloring to the mixture. Stir with a spoon or mix by hand until the mixture is smooth and firm like play dough. Add more water if needed.

2. Place the plastic bottle in the middle of the baking pan or on a large tray. Mold the dough mixture into a mountain shape around the bottle. Leave the top of the bottle open and be careful not to drop any dough in the bottle. Shape a channel or ridge in the mountain for the lava flow.

3. Move this project to a waterproof area or outside. Use a funnel to add ingredients to the bottle. Pour about two cups of warm water into the bottle. Add a few drops of orange food coloring, six drops of liquid detergent and two tablespoons of baking soda into the bottle. Wait a few minutes for the above ingredients to mix. Slowly pour vinegar into the bottle.

4. Watch the chemical reaction as liquid bubbles flow out of the bottle and down your mountain. This is a chemical reaction that is happening between the baking soda and vinegar.

5. To reuse this project, carefully pour all the liquid off the project and dry. Use different colors of food coloring to create different effects. To make a larger display, increase the ingredients proportionately. The diorama of the volcanic mountain can be enhanced with small trees, houses or dinosaurs.

Tips & Warnings

• Substitute play dough for the water and flour mixture.

• Use paper mache to build a permanent volcano.

• This experiment can be messy. Build in a waterproof area or outside.

References

• MBMG: Make a Chemical Volcano
• Oregon State: Volcano Models
• Volcano Live: How to Make a Volcano Model

Resources

• NOAA: Make Your Own Volcano