Question

Why is Aluminium corrosion useful?

Answer 1

Hint: The slow degradation of the metal due to the impact of air, water or any chemical reaction is called corrosion.
It is also defined as a natural process of conversion of metal into its more stable oxide.

Complete Step by Step Solution:
Aluminium is a metal which is present on earth in large amounts and because of its outstanding characteristics, is one of the most extensively utilized metals.
This metal has a great affinity toward oxygen. It is because it acts as a reducing agent.
Aluminium's electronic configuration is \[\left[ {Ne} \right]{\rm{ }}3{s^2}{\rm{ }}3{p^1}.\]

If it loses three electrons, it will attain the electronic configuration of Neon which is a stable noble gas configuration.
Hence, Aluminium when exposed to oxygen gets oxidised easily i.e., acts as a reducing agent.

When Aluminium gets exposed to air, it readily reacts with oxygen to form Aluminium oxide.

\[\begin{array}{*{20}{l}}{4Al\left( s \right){\rm{ }} + \;\;\;\;3{O_2}{\rm{ }} \to {\rm{ }}2A{l_2}{O_3}}\\{Aluminium{\rm{ }}Oxygen\;Aluminum{\rm{ }}Oxide.}\end{array}\]

This Aluminium oxide gets accumulated in the form of a thin layer on the surface of the metal.
This oxide is stable and non-reacting in nature. This oxide coating attaches itself to the surface of the metal adequately. It does not peel off. If there is an attempt in removing this layer, then the corrosion begins again.

This stable oxide layer prevents the surface of the metal from undergoing corrosion.

So, corrosion of Aluminium is useful.

Additional Information: Corrosion for most metals like Iron, Copper etc., is destructive. It results in massive destruction to buildings, bridges, ships and all other objects made of metals. Taj Mahal and Statue of Liberty are examples.

Note: Aluminium metal due to its high oxidation potential readily undergoes oxidation. Oxidation is defined as the process of loss of electrons. Due to oxidation, a stable layer of Aluminium oxide is created on the body of the metal which hinders further oxidation.