A Reaction Chamber for the Thermite Reaction The"therm~tr"or CAdsehmdt reamon is a dmrnnt~c,but potentrally haza d u w demonrtratwn prudurmg intemr heat and molrrn aron from the reduction of iron oxide by aluminum(1). The reaction releases copious amounts of smoke and flying sparks. We have built a see-through chamber (shown in the accompanying picture) to contain both the sparks and the smoke and to remove the smoke via a duct to a n exhaust system. The portable chamber, designed to fit through a doorway that is 6-ft 8-in. high by 36-in. wide, is made of 114-in. poly(methy1 methacrylate), commonly sold under the tradename Plexiglas. The front and sides of the chamber are double-walled. and the inner walls are constructed to slide out as a unit to facilitate cleking; it is mounted on a wooden base. We anticipate that the spark.; will eventually scar and pit the Plexiglas inner liner, necessitating its replacement after many repetitions of the demonstration. Ordinary 4-in. flexible plastic hose can be used ta canned the box to a n exhaust duct. If an exhaust duet is not readily available, a small exhaust fan i n the base could be used to remove waste gases through a fleldble hose to a n existing building window. Materials for the chamber cost less than $500; the labor costs were estimated a t $500. Construction plans suitable for a skilled craftsman are available for $5 from the Institute for Chemical Education, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706-1396. Phone (608) 262-3033; FAX (608) 262-0381.
Literature Cited 1. ShaWlashul,BassamZ.Ch~rmealDPm~stmBo"s:AHondbookbrTeoch~rsofChsmisfry,volume 1; University ofwiseonsin:Madison. WI,1983;pp 85-89.
Thomas L. Foseid Un vers ty of W~sconsn-Mad son
Madison, WI 53706
Volume 71 Number4 April 1994
327
