Water Starts A Fire

Purpose:

1. To show that a single drop of water can display a violent and vivid reaction between normally nonreactive materials.

Materials:

1. Water
2. Iodine crystals
3. Powdered aluminum
4. Metal pan
5. Mortar and pestle

Procedure:

1. Powder some iodine crystals in amortar and mix this powder with an equal volume of powdered aluminum. MAKE SURE BOTH SUBSTANCES ARE COMPLETELY DRY.
2. Place a little mound of the mixture in the center of the metal pan.
3. Make a small depression in the top of the mound.
4. (Due to the reaction that occurs, it is advised that this be done outdoors, or under a fume hood.) Add 2 or 3 drops of water in the depression on top of the mound, and STAND BACK!!
5. Instantly, purple-red vapors will rise from the heap. The mound will then burst into a beautiful purple-red flame, accompanied by a large volume of smoke.

Questions:

1. What allows there to be a reaction between the iodine and the aluminum?
2. What color was the flame that appeared?