Aluminium oxide - Al2O3

What is Aluminium Oxide (Al2O3)?

Al2O3 is an inorganic chemical reagent with chemical name Aluminium oxide. It is also called as Alpha-Alumina, alumina, alundum or aloxide.

Table of Contents

• Aluminium oxide Structure
• Properties of Aluminium oxide
• Chemical Properties of Aluminium Oxide
• Aluminium oxide Uses
• Frequently Asked Questions - FAQs

It is found naturally as corundum, Ruby’s, sapphires, and emeralds. It is an amphoteric substance, which reacts with both acids and bases. It occurs as solid and appears white. It is odourless and insoluble in water. The most common occurrence of this compound is in crystalline form, called α-aluminium oxide or corundum. Due to its hardness, is widely used and suitable to use as an abrasive and in cutting tools.

Aluminium oxide Structure

(Al2O3 Structure)

Properties of Aluminium oxide - Al2O3

Al2O3 Aluminium oxide Molecular Weight/ Molar Mass 101.96 g/mol Density 3.95 g/cm³ Boiling Point 2,977 °C Melting Point 2,072 °C

Chemical Properties of Aluminium Oxide

1. Reaction with sodium hydroxide

Aluminium oxide reacts with sodium hydroxide to produce sodium aluminate and water. This reaction takes place at a temperature of 900-1100°C. Salt and water are obtained in this reaction in which aluminium oxide acts as an acid.

Al2O3 + 2NaOH → 2NaAlO2 + H2O

2. Reaction with sulphuric acid

Metal oxides are generally basic in nature but aluminium oxide is amphoteric oxide.

Hence it acts both as acid and base. In this case, it acts as a base

Al2O3 + H2SO4 → Al2(SO4)3 + H2O

This is a neutralisation reaction.

3. Reaction with hydrochloric acid

Aluminium oxide contains oxide ions, and thus reacts with acids in the same way sodium or magnesium oxides do. Aluminium oxide reacts with hot dilute hydrochloric acid to give aluminium chloride solution.

Al2O3+6HCl → 2AlCl3+3H2O

Aluminium oxide (Al2O3 ) Uses

• Aluminium oxide is one of the common ingredients in sunscreen and is also present in cosmetics such as nail polish, blush, and lipstick.
• It is used in formulations of glass.
• It is used as a catalyst.
• It is used in the purification of water to remove water from the gas streams.
• It is used in sandpaper as an abrasive.
• Aluminium oxide is an electrical insulator used as a substrate for integrated circuits.
• Used in sodium vapour lamps.

Learn more about the chemical behaviour and importance of Aluminium oxide with the expert faculties at BYJU’S.

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Conductors Types Of Catalyst