Question

${\mathrm{Fe}}_2{\mathrm{O}}_3+2\mathrm{Al}\to {\mathrm{Al}}_2{\mathrm{O}}_3+2\mathrm{Fe}$

The reaction is an example of a:

• A. Combination reaction
• B. Double displacement reaction
• C. Decomposition reaction
• D. Displacement reaction.

Answer 1

The correct option is D

Displacement reaction.

An explanation for Correct answer:-

Option (D) Displacement reaction.

• A displacement reaction is one wherein the atom or a set of atoms is displaced by another atom in a molecule.
• The general equation for the displacement reaction is $\mathrm{AB}+\mathrm{C}\to \mathrm{AC}+\mathrm{B}$, where A is more reactive than B.

• In the reaction $\underset{\mathrm{Ferric}\mathrm{oxide}}{{\mathrm{Fe}}_2{\mathrm{O}}_3\left(\mathrm{aq}\right)}+\underset{\mathrm{Aluminium}}{2\mathrm{Al}\left(\mathrm{s}\right)}\to \underset{\mathrm{Aluminium}\mathrm{oxide}}{{\mathrm{Al}}_2{\mathrm{O}}_3\left(\mathrm{aq}\right)}+\underset{\mathrm{Iron}}{2\mathrm{Fe}\left(\mathrm{s}\right)}$, Aluminium being more reactive than Iron, displaces Iron and results in the formation of the Aluminium oxide.
• Hence option D is correct.

An explanation for incorrect answer:-

Option (A) Combination reaction.

• In a combination reaction where two or more elements or compounds (reactants) combine to form a single compound (product).
• The general equation for the combination reaction is $\mathrm{A}+\mathrm{B}\to \mathrm{AB}$.
• Hence option (A) is incorrect.

Option (B) Double displacement reaction

• In a double displacement reaction, two atoms or a group of atoms switch places to form new compounds.
• The general equation for the displacement reaction is $\mathrm{AB}+\mathrm{CD}\to \mathrm{AC}+\mathrm{BD}$.
• Hence option (B) is incorrect.

Option (C) Decomposition reaction

• Decomposition reactions are the process in which chemical species break up into simpler parts
• The general equation for Decomposition reaction is $\mathrm{AB}\to \mathrm{A}+\mathrm{B}$
• Hence option (C) is incorrect

Therefore, $\underset{\mathrm{Ferric}\mathrm{oxide}}{{\mathrm{Fe}}_2{\mathrm{O}}_3\left(\mathrm{aq}\right)}+\underset{\mathrm{Aluminium}}{2\mathrm{Al}\left(\mathrm{s}\right)}\to \underset{\mathrm{Aluminium}\mathrm{oxide}}{{\mathrm{Al}}_2{\mathrm{O}}_3\left(\mathrm{aq}\right)}+\underset{\mathrm{Iron}}{2\mathrm{Fe}\left(\mathrm{s}\right)}$, the reaction is an example of a Option (D) Displacement reaction.