$Fe_2O_3 + 2 Al \rightarrow 2Fe + Al_2O_3 + heat$ the given reaction is:

Question

Accepted Answer

The correct option is (2):

The given reaction, $Fe_2O_3 + 2 Al \rightarrow 2Fe + Al_2O_3 + heat$, represents a highly exothermic redox reaction where aluminum reduces iron(III) oxide. This specific reaction is known as the Thermit reaction. In this process, aluminum acts as a reducing agent, having a greater affinity for oxygen than iron. It pulls oxygen from iron(III) oxide, forming aluminum oxide and releasing molten iron along with a significant amount of heat. This reaction is famously used in thermite welding, particularly for joining railway tracks, and in incendiary devices due to the intense heat produced.

The incorrect option is (1): Adodising. Anodizing (also known as anodising) is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts, typically aluminum, to enhance corrosion resistance and wear. It is not a chemical reaction like the one presented.

The incorrect option is (3): Galvanisation. Galvanization is a process of applying a protective zinc coating to steel or iron to prevent rusting. This is usually done by hot-dip galvanizing, where the iron or steel is submerged in a bath of molten zinc. It is a coating process, not a displacement reaction where one metal reduces another to form a new compound.

The incorrect option is (4): All of the above. Since anodizing and galvanization are incorrect descriptions of the given reaction, this option is also incorrect. The reaction specifically describes the Thermit process.