Question

Why is aluminium used to join railway tracks or the cracked machine parts of ‘iron’? Write a balanced chemical equation for the reaction which occurs.

Hint:

Thermite reaction: Aluminium reduces iron oxide producing heat.

Answer 1

Aluminium's high reactivity makes it suitable for thermite welding. It removes iron from its oxide due to its strong oxygen attraction. The resulting heat melts the iron, fusing the broken pieces. The balanced chemical equation is: \[ Fe_2O_3 + 2Al \longrightarrow 2Fe + Al_2O_3 + \text{Heat} ]. This is the Thermite reaction. The molten iron then fills the space and hardens, uniting the metal components.