Thermit reaction demonstration

The thermit reaction demonstrates the reaction between aluminium powder and iron(III) oxide. It must be carried out as a teacher demonstration... 

An intimately powdered mixture, usually ignited by magnesium ribbon as a high-temperature fuse, reacts with an intense exotherm to produce molten iron and was used formerly (before the advent of gas or arc welding) in the commercial thermite welding process. Incendive particles have been produced by this reaction on impact between aluminium and rusty iron. (The term thermite reaction has now been extended to include many combinations of reducing metals and metal oxides) [1], Some accidents in demonstrating the thermite reaction are described [2],... 

Reduction of metal oxides by other metals (Figure 10.6, p. 154). Demonstrate the Thermit reaction and the reactions between the metals magnesium, zinc, iron and copper and their oxides. This will establish an order of reactivity for these metals. Some of these reactions are very violent so the use of small quantities and a rehearsal before the class demonstration are essential. R... 

The thermit reaction is an interesting demonstration of this (see page 238). A class experiment (page 239) illustrates the same point. 

An explosion injuring 27 people occurred when a thermite reaction was being demonstrated as part of a magic show at an engineering open house. The demonstration, which generated molten iron in a 2,500 to 3,000 °C reaction, was being carried out in a clay flowerpot above a beaker of water and sand to show the heat produced by the reaction when molten iron particles fall into water. Suddenly, the demonstration exploded, sending hot metal and water toward the audience. 

In the thermite reaction, aluminum powder is reacted with iron(III) oxide to form elemental iron and aluminum oxide. The reaction produces an extremely large amount of energy in the form of heat, making it useful both as a dramatic chemistry lecture demonstration and in the welding of railroad tracks. If 20.0 g of A1 powder are reacted with 50.0 g of iron(in) oxide, what mass (in grams) of Fe will be produced, assuming that at least one of the reactants is completely used up. 

In demonstrating the use of powdered aluminium to reduce the oxide in a thermite-type reaction, the mixture must be heated behind a safety screen because of the small explosion produced [1]. Consolidation of the thermite mixture into a high-density composite gives chemical heat sources which are safe to handle [2],... 

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