Question

What is a thermite reaction? Explain with the help of an equation.

Answer 1

The reduction of a metal oxide to form metal by using aluminium powder as a reducing agent is called a thermite reaction (or thermite process).

The reactions between metal oxides and aluminium powder that yield metals are highly exothermic, releasing a substantial amount of heat. The quantity of heat generated is sufficient to melt the metals. The reduction feature of aluminium is utilised in thermite welding to join fractured heavy iron items such as girders, railway tracks, or damaged machine components.

A mixture of iron (III) oxide and aluminium powder is ignited with a burning magnesium ribbon. Aluminium reduces iron oxide to produce iron metal, with the evolution of a large amount of heat. Due to this heat, iron metal is produced in the molten state.

\[\ce{\underset{Iron (III) oxide}{Fe2O3_{(s)}} + \underset{(Reducing agent)}{\underset{Aluminium powder}{2Al_{(s)}}} -> \underset{(Molten state)}{\underset{Iron metal}{2Fe_{(l)}}} + \underset{Aluminium oxide}{Al2O3_{(s)}} + Heat}\]