Students should already have a basic knowledge of volcanoes and know that molten rock, or magma, contained deep in the earth comes out as lava when the volcano erupts. The purpose of building a model of an erupting volcano is to help children learn more about volcanoes and what happens when they erupt. They will also learn what chemical reaction occurs when mixing vinegar and baking soda.
For this project you will need a baking sheet or aluminum pie tin and newspaper. Each of these will be used to catch any spills and lessen the mess of the project. From your kitchen gather baking soda, vinegar, dishwashing soap and red food coloring. You will also need modeling clay, a funnel, a measuring spoon, a measuring cup and small plastic bottle. The bottle should be about the size of an 8-ounce water bottle.
Wash the bottle well before using it in the experiment. Place the bottle onto the baking sheet. Form a mound of modeling clay in the shape of a volcano around the bottle, making sure to leave the opening of the bottle clear. Put 3 to 4 tbsp. baking soda into the bottle. Next add a few drops of dishwashing soap and 1/2 cup water. Mix a few drops of red food coloring into 1/2 cup vinegar. Do not add this mixture to the bottle until you are ready to erupt the volcano.
To make the volcano erupt, pour the vinegar and food coloring mixture into the bottle using a funnel. Move the funnel out of the way quickly, since the eruption will happen immediately. Since vinegar is an acid and baking soda is a base, the two ingredients interact and neutralize each other. This process causes carbon dioxide gas to be produced as a by product which produces the "explosion" out of the top of the bottle.