Properties of Aluminium

What is Aluminium?

Aluminium is a prominent “group 13” element, a member of the Boron family. Electronic configuration of Aluminium is 1s2 2s2 2p6 3s2 3p1.

Due to an additional electron orbit in comparison to Boron, the sum of the first three ionization enthalpies of Aluminium is low in comparison to Boron and is, therefore, able to form Al3+ ions. It is a highly electropositive element and generally furnishes +3 oxidation states, as in the case of Aluminium Oxide (Al2O3).

Other known oxidation states are +2 and +1. It is often protected by a layer of inert transparent Aluminium oxide (Al2O3) that forms rapidly in the air but is found to be highly reactive in nature. Aluminium forms amphoteric oxides, that is, it shows both acidic and basic character. Read more about electron configuration here.

Table of Contents

Physical Properties of Aluminium

  • Aluminium has a lower density than any other commercial metal except magnesium. Given the right type of surface, aluminium makes an excellent reflector, especially for ultraviolet light.
  • Aluminium is an odourless, tasteless, silvery-white metal. With increasing silicon and ductile and quite soft. The aluminium crystal has a face-centred cubic structure.
  • The concentration of the lattice in the less pure metal results from the formation of impurity segregations. Purity also affects most other physical properties.
  • Aluminium has a lower density than any other commercial metal except magnesium.
  • Aluminium may also be used as a selective cold or hot wall or as a body approximating the effect of a black body. In the infrared region, the reflectivity of aluminium is exceeded only slightly by that of gold and silver.

Chemical Properties of Aluminium

1. Reaction of Aluminium with Air

Generally, Aluminium metal does not react with air as its surface is covered with a thin layer of oxide that helps protect the metal from attack by air. However, in case the oxide layer gets damaged and the Aluminium metal gets exposed, it reacts again with oxygen forming amphoteric oxide (Aluminium (lll) Oxide), Al2O3.

4Al (s) + 3O2 (l) → 2Al2O3 (s)

2. Reaction of Aluminium with Acids:

Aluminium reacts readily with mineral acids to form solutions containing aquated Al (lll) ion along with the liberation of hydrogen gas, H2. For example, it dissolves in hydrochloric acid (HCl) liberating dihydrogen gas.

2Al(s) + 6HCl (aq) → 2Al3+ (aq) + 6Cl(aq) + 3H2 (g)

In case of reaction with Nitric acid, it reacts passively by forming a protective oxide layer on its surface of Aluminium Oxide.

Al2O3 +6 HNO3 → 2Al(NO3)3 + 3H2O

3. Reaction of Aluminium with Alkalis

Aluminium reacts with alkalis to form aluminates along with the liberation of hydrogen gas, H2. Comparable electronegativity of Oxygen and Aluminium makes it possible for Aluminium to form covalent bonds with oxygen. This can be seen as a prominent reason for the formation of aluminates. For example, Aluminum reacts with hot, concentrated sodium hydroxide solution to produce a colourless solution of sodium tetrahydroxoaluminate along with the evolution of dihydrogen gas.

2Al (s) + 2NaOH (aq) + 6H2O → 2Na+ (aq) + 2[Al(OH)4] + 3H2 (g)

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Frequently Asked Questions – FAQs


What are the properties of aluminium?

It has low density, is non-toxic, has high thermal conductivity, has excellent resistance to corrosion, and can be cast, machined and moulded quickly. It’s non-magnetic and non-sparking as well. It is the second most ductile and the sixth most malleable metal.


Why is Aluminium used in aircraft?

Since it’s lightweight and solid, aluminium is suitable for aircraft construction. Aluminium is about a third of steel’s weight, making it easier for an aeroplane to bear more weight and/or become more fuel-efficient. In addition, aluminium’s high corrosion resistance assures the safety of the aircraft and its passengers.


What is the chemical property of Aluminium?

Aluminium is a metal which is flexible and lightweight. Due to a thin film of oxidation that occurs rapidly as it is exposed to sunlight, it has a dull silver look. Aluminium is non-toxic , non-magnetic and non-sparking (like metal). Aluminium only has one isotope that exists naturally, aluminium-27, which is not radioactive.


Is aluminium a conductor?

Conductors consist of electric current-conducting compounds or electron flow. Usually, non-magnetic metals are known to be perfect electricity conductors. A variety of metal conductors are used by the wire and cable industry, but the two most common are copper and aluminium.


What are 3 uses of aluminium?

Aluminium is malleable and delicate. In a wide range of items, from cans, foils, cooking utensils, and window frames where aluminium is included.

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