Share facts or photos of intriguing scientific phenomena.

How to Build a Model Volcano for School

A 9-point Guide on How to Build a Model Volcano for School

Making the model of a volcano that erupts is not difficult, provided you use the required ingredients in the right quantities. For your volcano to explode, you will require baking soda and vinegar as the main ingredients along with other supplies.
Ningthoujam Sandhyarani
Last Updated: Sep 25, 2017
The topics for science fair projects are many, but there are few things that you should consider if you want to make your project an award-winning one. For example, it should be less time-consuming, or you will run out of time on the day of the competition. Other tips include using easily available and safe chemicals, and most importantly, getting the desired results. One project that meets all these criteria is 'making a volcano model'.
How to Make a Volcano that Erupts
The interesting part with making a volcano for a science fair project is watching it actually erupt. With a volcano project, there are high chances of fetching good results, as it can work really well if executed properly. Otherwise, there are other project ideas, which seem interesting but are extremely difficult to execute, and have less chances of having positive outcomes. Moreover, a volcano project requires easily available supplies. Hence, finishing your project within the time limit is not much of a challenge. Also, you can use your creativity to make the volcano model appear like a real exploding one.
Before you actually start preparing for the project, research about the volcanic eruption process, so that you will be able to explain your model better, and also answer questions raised by others. As a volcano erupts, molten rock from below the Earth's crust or magma is brought to the surface as lava. In a model volcano, the explosion part is based on the reactions between baking soda (a base) and vinegar (an acid), giving a fizzy and bubbly liquid that rises upwards.
Supplies for Making a Volcano Model
  • Spare newspapers
  • Aluminum or thick paper plate
  • A one-liter plastic bottle (soda bottle)
  • Flour dough (or modeling clay)
  • Warm water, 1 cup
  • A few drops of red food coloring
  • Dishwashing liquid, 1 tablespoon
  • Baking soda, ½ cup
  • Vinegar, ¼ cup
Directions for Making a Volcano Model
  • First of all, let's work on preparing the flour dough. In a large bowl, combine 6 cups of flour with 2 cups of water, 1½ cups salt, and 3 tablespoons cooking oil. Mix well to make a smooth dough.
  • Lay spare newspapers on a table, and place an aluminum plate over them to form a base for the model. Cut the top narrow portion of the soda bottle (which will serve as a crater), and position it in the center of the plate.
  • Mold the flour dough (or modeling clay) around the bottle in a cone shape so that it resembles a volcano. But make sure that the bottle opening is not covered or clogged with the dough.
  • Add some plant twigs, sand, small rocks, and pebbles to impart a real touch to the model. You can refer to the picture of a volcano, and try to mimic it with respect to its shape and appearance.
  • Carefully pour warm water in the soda bottle, and add a few drops of food coloring. Add detergent in the water and food coloring mixture.
  • In this homemade science project, the detergent is useful for creating bubbles, and upward rising of lava. Without wasting time, add baking soda in the concoction.
  • In the next step, pour vinegar (acetic acid) to the baking soda (sodium bicarbonate) mixture for initiating the acid-base reaction.
  • Be careful as it is explosion time, and maintain a safe distance from the exploding volcano. Within a few minutes time, you will notice a red colored, foamy mixture flowing out of the crater.
The following is the acid-base reaction that takes place when vinegar combines with baking soda.
In simple words, Acetic acid + Sodium bicarbonate → Carbon dioxide gas + Sodium acetate + Water. 
The carbon dioxide gas builds up the pressure inside the volcano. This gas is also produced in a real volcanic eruption. The foaming effect of a detergent helps the bubbly mixture rise and squirt from the bottle opening. The red food coloring adds an original touch to the overflowing lava.