Intermediate Topic 636 of 1102 Inorganic Chemistry
Aluminium Chemistry
Aluminium forms a protective oxide layer and amphoteric oxides and hydroxides.
In-depth explanation of Aluminium Chemistry
Aluminium is the most abundant metal in Earth's crust, and it resists corrosion because it forms a thin, adherent layer of aluminium oxide. The oxide is amphoteric, and aluminium dissolves in both acids and bases, so it reacts with hot sodium hydroxide to release hydrogen. Aluminium salts hydrolyse in water to give acidic solutions because Al3+ is small and highly charged. Aluminium chloride is a strong Lewis acid used in Friedel-Crafts reactions. The metal is light, strong when alloyed and a good conductor, and it is easy to recycle.
Going deeper: Aluminium Chemistry
Key ideas: Al is amphoteric: Al2O3 + 6HCl gives 2AlCl3 + 3H2O and Al2O3 + 2NaOH + 3H2O gives 2Na[Al(OH)4]. It is passivated by a thin oxide layer, so it resists corrosion despite E0 of -1.66 V. AlCl3 is a covalent dimer Al2Cl6 in the vapor and a Lewis acid catalyst in Friedel-Crafts reactions. Al hydroxide dissolves in excess base but not in excess ammonia.
Common mistakes and connections: Students claim aluminium is unreactive because it is passivated; it is intrinsically very reactive, as shown when the oxide is scratched or amalgamated. AlCl3 is not ionic as the Fajans rule predicts. Hydrated Al3+ is acidic, with pKa near 5. Connects to alums, extraction, and thermite reaction.
Visualization of Aluminium Chemistry
Aluminium has three valence electrons (3s2 3p1) and forms the small, highly charged Al3+ ion that hydrolyses water and gives an amphoteric oxide. The interactive lesson shows this as a live animation or chart.
Worked example and use case
Aluminium reacts with sodium hydroxide solution: 2Al + 2NaOH + 6H2O giving 2NaAl(OH)4 + 3H2.
Frequently asked questions about Aluminium Chemistry
What is Aluminium Chemistry?
Aluminium forms a protective oxide layer and amphoteric oxides and hydroxides.
Is Aluminium Chemistry a beginner, intermediate or advanced topic?
Aluminium Chemistry is a intermediate topic in Inorganic Chemistry. It builds on the vocabulary of beginner topics in this area.
What should I learn before Aluminium Chemistry?
Study these earlier topics in Inorganic Chemistry first: Boron Family, Borax, Boranes.
What comes after Aluminium Chemistry?
The next topics in Inorganic Chemistry are Alums and Extraction of Aluminium.
Can I practise Aluminium Chemistry with quizzes?
Yes. The interactive lesson includes a self-check question on Aluminium Chemistry, and the Inorganic Chemistry quiz draws on every topic in this area.
Where Aluminium Chemistry fits in Inorganic Chemistry
Aluminium Chemistry is topic 21 of 113 in Inorganic Chemistry.