Question

Give reasons for the following:
The reaction of iron (III) oxide [Fe₂O₃] with heated aluminum is used to join cracked machine parts.

Answer 1

The reaction of iron (III) oxide with heated aluminum is a displacement reaction which is highly exothermic in nature. The amount of heat evolved is so large that the metals are produced in the molten state due to which this reaction is used to join cracked machine parts. 

\[\ce{Fe2O3(s) +2Al(s)->2Fe(l) + Al2 O3(s) + heat}\]