Thermite

2al + Fe203 = 2FE + AL2o3

This is a very hot reaction. Temperatures can reach over 4,000 F! Thermite has many uses. The most common one is welding railroad tracks to this day. It has some military uses also. The first demo shows you the energy of thermite with some rusty balls!

Concepts:

Exothermic reactions,

Safety:

  • Safety glasses for all

  • 10' standoff distance

  • Don't smash your fingers!

Equipment:

Preparation:

  • Sand off the chrome coating to let the steel ball rust. More rust the better!

  • Wrap one ball in foil

Demonstration Instructions

  • Hold the balls in your hands so they protrude a bit as you are going to hit them together.

  • Start off by doing this slowly to get the hang of it.

  • Once you think you got it, swing with greater speed! Turn off the lights and WHAM!

  • You can repeat immediately, but rotate the ball to get a fresh spot of rust and foil.

  • Start at 25 sec. https://www.youtube.com/watch?v=WHgwgLENQrU

Observations:

  • You will see sparks fly out from the balls quickly and disappear!

Learning Outcomes:

  • Exothermic reactions, transfer of oxygen,

  • Nefarious activity with homemade explosives

  • Identify the precursors

Chemical Disposal:

None

Additional Information:


Do not try at home

We had to practice this demo a few times to get the correct reaction. It takes quite a bit of activation energy to get the reaction to take place. The iron oxide and aluminum oxide were in a clay pot but needed some magnesium wire and flare to activate it. Not something you can do as an everyday demo. But this video is available as a replacement! In this video we use about a 10 pound mixture.

Thermite demo start at 3:30 min; https://www.youtube.com/watch?v=PfJMWMsRszY