What is a chemical property?
A chemical property is a property of a substance that can be seen when it undergoes a chemical reaction.
Chemical Properties of Aluminium:
(a). Reaction with air:
Aluminium is not affected by dry air.
Aluminium burns brightly at \(800\)°C to form its oxide and nitride.
\(4Al\) + \(3O_2\) → \(2Al_2O_3\) (Aluminium oxide).
\(2Al\) + \(N_2\) → \(2AlN\) (Aluminium nitride).
(b). Reaction with water:
Water does not react with aluminium because of the oxide layer on it. When steam is passed over, the red hot aluminium produces hydrogen.
\(2Al\) + \(3H_2O\) → \(Al_2O_3\) + \(3H_2\)↑
(Aluminium) + (Steam) → (Aluminium oxide) + (Hydrogen)
(c). Reaction with alkalis:
Aluminium reacts with caustic soda alkalis to form aluminates.
\(2Al\) + \(2NaOH\) + \(2H_2O\) → \(2NaAlO_2\) + \(3H_2\)↑
(Aluminium) + (Caustic soda) → (Sodium meta-aluminate)
(d). Reaction with acids:
Aluminium reacts with dilute or con. \(HCl\) liberates \(H_2\) gas.
\(2Al\) + \(6HCl\) → \(2AlCl_3\) + \(3H_2\)↑
(Aluminium) + (Hydrogen chloride) → (Aluminium chloride) + (Hydrogen)
Aluminium reacts with dilute sulphuric acid releases hydrogen, similarly reacts with hot concentrated sulphuric acid releases sulphur dioxide.
\(2Al\) + \(3H_2SO_4\) → \(Al_2(SO_4)_3\) + \(3H_2\)↑
\(2Al\) + \(6H_2SO_4\) → \(Al_2(SO_4)_3\) + \(6H_2O\) + \(3SO_2\)↑
Dilute or concentrated nitric acid does not react with aluminium, but it does render it passive by forming an oxide film on its surface.
(e). Reducing agent:
Aluminium is a highly effective reducing agent.
When a mixture of aluminium powder and iron oxide is ignited, the latter is reduced to metal. This process is known as the aluminothermic process.
\(Fe_2O_3\) + \(2Al\) → \(2Fe\) + \(Al_2O_3\) + Heat.
Uses of Aluminium:
Aluminium is used in various applications.
(a). Household utensils.
(b). Electrical cable industry.
(c). Manufacturing of aeroplanes and other industrial machinery parts.
Industrial usage of aluminium