Question

Which type of reaction is the following? \[ \mathrm{Fe_2O_3 + 2Al \rightarrow Al_2O_3 + 2Fe} \]

• A. Addition reaction
• B. Double displacement reaction
• C. Dissociation reaction
• D. Displacement reaction

Hint:

Displacement reactions involve one element replacing another in a compound, often accompanied by electron transfer (redox).

Answer 1

The Correct Option is D

The given reaction is a
displacement reaction and a classic example of a redox (reduction-oxidation) process. In this reaction, aluminum (\( \mathrm{Al} \)) displaces iron (\( \mathrm{Fe} \)) from iron oxide (\( \mathrm{Fe_2O_3} \)) because aluminum is more reactive. The balanced chemical equation is: \[ \mathrm{2Al + Fe_2O_3 \rightarrow Al_2O_3 + 2Fe} \] \smallskip 1.
Nature of the Reaction:

Aluminum replaces iron in iron oxide, displacing it as elemental iron.
Aluminum is oxidized while iron ions are reduced.
\smallskip 2.
Redox Process:


Oxidation (Aluminum): \[ \mathrm{4Al \rightarrow 4Al^{3+} + 12e^-} \]

Reduction (Iron): \[ \mathrm{2Fe^{3+} + 6e^- \rightarrow 2Fe} \]
\smallskip 3.
Thermite Reaction:

This reaction is called the
thermite reaction.
It is highly exothermic, generating intense heat and molten iron.
Used extensively in welding (e.g., railway tracks) and metal extraction.
\smallskip 4.
Applications:

Producing pure iron without external heating.
Demonstrates the reactivity series, where a more reactive metal displaces a less reactive metal from its compound.
\smallskip In summary, aluminum reduces iron oxide to iron while oxidizing to aluminum oxide in a displacement redox reaction known as the thermite reaction.