Backdraft Lesson 
2003 Reader Submission
Pending Acceptance
High school chemistry is a time when you get to explore the many miraculous physical laws of the universe. My high school chemistry teacher believed deeply that as students, we should be exposed to as many and as interesting reactive situations as possible. But even as a teacher of many years, one may be prone to mistakes at times.
Our teacher announce that this class was going to begin with basic lessons on combustion. Lecture consisted of identifying the three basic components needed in any combustive reaction; fuel, oxygen and heat.
As a finally we were to observe a spectacular lesson that graphically displayed the primal elements of combustion...Backdraft.
To recreate this experiment all you need is an empty 5 gallon sparklets water bottle, a little ethynol, a couple pieces of paper and a match. The basic principal of a backdraft states that when unburned heated gases are exposed to air they rapidly combust creating an explosion or blast of energy.
So our teacher put the ethynol in the bottle, cover the top with a piece of paper. Next he lit another piece of paper and stuffed it down the neck of the bottle, quickly replacing the cover sheet. The paper in the bottom of the bottle burned well, and all seemed under control. The lights were turned off, the cover removed and a blast of flame spewed forth from the mouth of the bottle. COOL! It looked like Tom Cruise had turned on the afterburners in his F-14 right in the middle of class. We convinced the teacher to recreate the effect for a second time.
The same procedure was followed, but the heat source refused to remain lit. The teacher understood the cause right away, and used this as a lesson for the class. "Students, what are the three elements needed for combustion?" We rattled them off excitedly. Heat...we had that. Fuel...that too. Oxygen...hmmmmm. Perhaps we had burned off all the oxygen in the bottle on our last attempt. In his ultimate wisdom, the teacher decided to correct the situation by saturating the interior of the bottle with pure oxygen.
The heat source was lit, and stuffed into the bottle. Within seconds there was a loud explosion. The bottle separated 3 inches from the base, launched through the ceiling tiles, plastic shards exploded out in a large radius from the launch site. Students and teacher sat stunned, covered in dust from the ceiling tiles as the fire alarm began to ring.
The teacher and a few students suffered only mild shock and hospitalization wasn't required. Luckily... Submitted on 08/27/2002
Submitted by:
Aaron Foellmi
Reference:
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