# Thermite

This demo is potentially one of the most dangerous offered. Let the demonstration technician know if you would like us to personally perform this demo for your class if you are not comfortable performing it yourself.

## Summary

Molten, white hot iron is made by igniting aluminum power and iron (III) oxide with a magnesium strip resulting in spectacular display of heat and light.

$$\ce{ Fe2O2 + 2Al -> 2Fe + Al2O3 ~~~~ \Delta G = -840 kJ/mol }$$

## Hazards

• The molten iron is white hot!! Use care!!
• Never use water or glass in any combination to catch the molten thermite.
• Be sure there is a depression in the sand for capturing the molten metal. Make sure that the molten iron will fall into the sand and not hit the sides of the bucket.
• Do not make the reaction too big!!
• The reaction is very exothermic! Everyone must stand back!
• Keep away from all possible flammable materials including papers, backpacks, projector screens.

## Chemicals and Solutions

Thermite and thermite starter: our thermite is called black powder thermite (Iron (II,III) oxide, while the starter is red thermite (Iron (II) oxide). Black powder thermite produces more iron but is harder to ignite while red thermite is easier to ignite but produces less iron. Thus a small layer of red thermite is placed on top of the black powder thermite and the red thermite is ignited.

## Materials

• Flower pot
• Ringstand and ring to hold flower pot
• Enamel bucket half filled with sand
• 2.5 inch Magnesium ribbon
• Bunsen burner
• Matches
• Tongs

## Procedure

1. Fill bucket about half full with sand.
2. Set up flower pot and ring stand such that pot hangs over center of the bucket.
3. Cover hole in pot with piece of filter paper.
4. Pour in about 1/2 inch of thermite powder.
5. Cover thermite with thermite starter powder.
6. Thermite can be ignited in a couple of different ways.
1. First, the Mg ribbon can be ignited using a bunsen burner flame. The ribbon can then be dropped into the flower pot, igniting the thermite.
2. Second, the Mg ribbon can be inserted into the powder like a fuse, then lit with the bunsen burner.
7. Turn off classroom lights so class can better appreciate the reaction.
8. Lift red hot iron metal out of sand with tongs.