Aluminium Reactions: Acids and Alkalis

Aluminium is widely employed in industry and in our daily lives due to its large reserves and good characteristics. The Hall–Héroult technique, developed separately by French engineer Paul Héroult and American engineer Charles Martin Hall in 1886, made aluminium much more accessible to the general people, and mass manufacturing led to its widespread use in industry and everyday life. Despite its widespread presence in the environment, no living thing is known to employ aluminium salts in their metabolism; yet, plants and animals tolerate aluminium well. Because of their abundance, the possibility of a biological role for these salts has piqued researchers curiosity, and research is ongoing.

Properties of Aluminium

Physical properties

The metal aluminium has a silvery-white look. It’s a light and airy metal. It’s also non-toxic and corrosion-proof. Thermal and electrical conductivity are both high. Its density is extremely low. In cold water and organic solvents, aluminium is insoluble. It is easily soluble in alkalis and dilute hydrochloric acid. Aluminium’s melting and boiling points are 933K and 2740K, respectively.

Chemical properties

Aluminium’s reaction with acids:

Aluminium interacts with a variety of acids, including

Hydrochloric acid reaction

Aluminium becomes aluminium chloride and hydrogen gas when it combines with dilute hydrochloric acid.

2Al+6HCl→2AlCl3+3H2

Using Sulphuric Acid as a Reagent

Aluminium combines with dilute sulfuric acid to generate aluminium sulphate, releasing hydrogen gas in the process (the gas evolved will be at a slow rate).

2Al + 3H2SO4 → Al2(SO4)3  + H2

 Aluminium dissolves in hot concentrated sulphuric acid, generating aluminium sulphate and water, as well as sulphur dioxide.

2Al + 6H2SO4 → Al2(SO4)3 + 3SO2 + 6H2O

Nitric Acid Reaction

Aluminium forms aluminium nitrate and ammonium nitrate when it combines with dilute nitric acid.

8Al + 30HNO3 → 8Al(NO3)3 + 9H2O +  3NH4NO3 

When strong nitric acid is used to treat aluminium, a layer of metal oxides forms on the metal’s surface, preventing further action or making the metal passive. As a result, aluminium containers can be used to transport concentrated nitric acid.

Aluminium reacts with alkali

When aluminium is exposed to hot alkalis, it produces meta aluminate and hydrogen.

2Al+ 2NaOH + 2H2O → 2NaAlO2 + 3H2

Aluminium forms halides when it reacts with halogens. Aluminium, for example, interacts with chlorine to generate aluminium chloride.

2Al + 3Cl2 → 2AlCl3

Aluminium interacts with bromine to generate aluminium bromide (AlBr3), iodine to form aluminium iodide (AlI3), and fluorine to form aluminium fluoride (AIF3).

Reaction with air

When aluminium reacts with oxygen, a protective coating of aluminium (III) oxide forms, which prevents the metal from reacting with oxygen again. Because of this, aluminium is known as a corrosion-resistant metal.

Aluminium produces a dazzling white flame when exposed to oxygen. This reaction also produces aluminium (III) oxide as a byproduct.

4Al+ 3O2 → 2Al2O3

Uses

• Aluminium is used to make cooking utensils, picture frames, home fittings, and other items since it is inexpensive and corrosion resistant.
• Aluminium is a good electrical conductor. As a result, it’s used in the production of electric transmission cables and wires.
• Because it inhibits corrosion, powdered aluminium is used as a silvery white coating for iron poles.
• Food, soaps, cigarettes, and other products are packaged with aluminium foil.
• Ammonal is a blend of aluminium powder and ammonium nitrate that is used as an explosive.
• In the extraction of metals, aluminium is employed.
• It’s used to make alloys.

Other properties

Low density

Aluminium has a density of 2.7g/cm3, which is just one-third that of iron and copper. Furthermore, aluminium has good ductility, with two-thirds the electrical conductivity of copper wire, but the quality is only one-third that of copper, and the price is less. As a result, aluminium is widely employed in the production of high-voltage wires and cables, as well as in the radio industry.

Thermal conductor

Aluminium is a good heat conductor (the thermal conductivity is three times greater than iron). Aluminium is utilised in the manufacturing of heat exchangers, heat sinks, and cooking utensils, among other things.

Ductility

Aluminium is ductile (second only to gold and silver) and can be produced into aluminium foil thinner than 0.01 mm at temperatures ranging from 100 to 150 degrees Celsius. Aluminium foils are commonly used to package cigarettes, candy, and other items.

High Corrosion Resistance

Aluminium forms a dense oxide protective film on its surface in the air, making it corrosion resistant. As a result, it is frequently employed in medical devices, chemical reactors, refrigeration equipment, petroleum refining equipment, oil and gas pipelines, and other applications.

Catalyst

Smelting refractory metals and welding rails are both common uses for thermite. In steelmaking, aluminium is also used as a deoxidiser. Aluminium powder, graphite, and titanium dioxide (or other high melting point metal oxides) are uniformly mixed, coated on metal, and calcined at high temperatures to create high-temperature resistant cermets, which have vital applications in rocket and missile technology.

Conclusion

Aluminium is a chemical element of group 13 with the symbol Al. It belongs to the periodic table’s group 13 and period 3. We learned a lot about the metal aluminium in this article. The chemical symbol, its occurrence, preparation, physical and chemical properties, and applications are all listed below. Aluminium may interact with a variety of other elements to generate a wide range of combinations.