Q22E - Chemistry (OpenStax)

Question

Why is it possible for an active metal like aluminium to be useful as a structural metal?

Step-by-Step Solution

Answer

The formation of aprotective coating on metal surface is referred to as passivation. This is the reason  that helps an active metal like aluminium to be useful as a structural metal.

Step 1:Aluminiumoxide

Aluminium oxide's high melting point makes it an excellent refractory material for lining high-temperature appliances such as kilns, furnaces, incinerators, reactors of various types, and crucibles.

Aluminium oxide\(\left( {{\rm{A}}{{\rm{l}}_{\rm{2}}}{{\rm{O}}_{\rm{3}}}} \right)\) is most commonly used in the production of metal aluminium (Al).

Step 2:Reason for the possibility of aluminium to be useful as a structural metal

It is possible to use Al in construction because of passivation. It is a process in which an aluminium oxide layer forms on the outer surface of ametal and protects the rest of the metal from reacting.

Step 3: Uses of Aluminiumoxide

• Aluminium is used as a structural metal even after it has been used as an active metal due to its properties like toughness, high strength, lightweight, and resistance to the corrosion process.

 

• It is corrosion-resistant because the formation of a protective aluminium oxide film on its metal surface suppresses its reactivity.

 

 

• The formation of aprotective coating on metal surface is referred to as passivation.