Question

“Displacement reactions also play a key role in extracting metals in the middle of the reactivity series.” Justify this statement with two examples.

Answer 1

Displacement reactions occur when a more reactive metal displaces a less reactive metal from its compound. This property is crucial in extracting metals from their ores, especially those that are in the middle of the reactivity series. Here are two examples to justify this statement:

i. Copper (II) Sulfate and Zinc: When zinc is added to copper (II) sulfate solution, zinc, being more reactive than copper, displaces copper from the solution. The reaction is represented as:

\[\ce{Zn + CuSO4 ​-> ZnSO4 ​+ Cu}\]

In this reaction, zinc sulfate is formed and copper is deposited. This illustrates how a more reactive metal (zinc) can extract a less reactive metal (copper) from its compound.

ii. Iron (III) Chloride and Aluminum: When aluminium is introduced to iron (III) chloride solution, aluminium, which is more reactive than iron, displaces iron from the compound. The reaction is represented as:

\[\ce{2Al + 3FeCl3 ​-> 2AlCl3 ​+ 3Fe}\]

Here, aluminium chloride is formed, and iron is released. This demonstrates the ability of aluminium to extract iron from its chloride due to its higher reactivity.