Earth to Class

Model Volcano Project

James Signorelli
Dwight Morrow High School
Science Department

The purpose of this project is to produce a model that simulates the building processes found in actual volcanoes. These processes include the layering of ash from the eruption to builds the cinder cone. They also show how the mass of the cone in time causes the Caldera to form when the crater collapses in on itself. A model can also be made that simulates the violent eruptions of a composite volcano. For this model, additional chemicals are required to produce the violent explosive eruption responsible for hurling dust and pyroclastic bombs into the air.

Phase #1 - the mountain

Obtain a piece of thick corrugated paper and line with several layers of aluminum foil. This is your primary fire shield.
Place a large, ceramic crucible in the center of the board and anchor with wall board joint compound.
[Available from Home Depot at $ 10.00 / 5 gallon pail]
Make a skeleton of the mountain with shaped layers of corrugated paper in the form of a top-o-graphic map.
Cover the layers with the wall board joint compound until your mountain has the desired shape.
Allow model to dry for several days. You may scratch in detail such as ravines and depressions before the plaster hardens. Plaster has a natural tendency to shrink and crack, adding realism to the surface of the model.
Paint the model by first spraying with BBQ black. Use Tempera paint for all other detail.

Phase #2 – the chemicals [cinder cone model]

Perform this Demonstration in a fume hood or outdoors for proper ventilation. Treat the ash as hazardous chemical waste and recycle for proper disposal. Vacuum or sweep up all ash.

Obtain Ammonium Dichromate from the chemical storage area of your school. It is stored in the oxidizer cabinet.
Place approximately one table spoon of Ammonium Dichromate into the crucible.
Light the chemical with a match and step back. The effect is more graphic in a darkened room.
The orange Ammonium Dichromate burns in a firey plume (fountain) into chromic oxide, a green colored ash.
The ash builds layer upon layer to form the cone.
As the ash cone reaches higher and higher, it becomes unstable and collapses in on itself to form the broad Caldera, from the crater.

Phase #3 – the chemicals [composite volcano model]

This model requires the use of an explosive mixture of chemicals. Do NOT use more than ½ teaspoon and do not pack it into the crucible.

In a non-flammable container, mix equal parts of table sugar and Potassium Chlorate. Stir, do not use a motor & pestle.
This mixture does not like friction!
Place approximately ½ teaspoon of the mixture into the large crucible.
Completely cover this mixture with the Ammonium Dichromate as in the Cinder Cone model. None of the sugar mixture should be visible. This works best if ¾ inch or more of the dichromate crystals covers the sugar mixture.
Light the model as in phase #1. Stand back! When the dichromate eventually reaches the sugar layer, the volcano becomes Mt. Saint Helen. The carbon balls (pyroclastic bombs) land several inches from the model. The center of the cinder cone is blown away, producing a very wide crater. If you don’t tell the students that this final reaction is due any minute, the surprise really gets their interest!

Please… Use professional judgment.

Don’t allow students to handle any of the chemicals.

Practice safe use of all chemicals

Start with small quantities and develop your learning curve before trying this in front of a class.

Treat all fuel, ash and waste as a hazardous chemical. Dispose of properly.