Definition

Noun 1. A chemical compound: Aluminium chloride is an inorganic compound with the chemical formula AlCl₃. It is primarily used as a catalyst in chemical reactions and as a wood preservative.

Usage Examples

• The chemist added aluminium chloride to the reaction mixture to act as a catalyst.
• Aluminium chloride is applied to lumber to protect it from fungal decay and insects.
• In the laboratory, anhydrous aluminium chloride must be handled in a dry environment as it reacts violently with water.

Advanced Usage

• As a Lewis acid catalyst: In organic chemistry, anhydrous aluminium chloride is a classic and powerful Lewis acid catalyst, essential for reactions like Friedel-Crafts alkylation and acylation.
  • Example: Anhydrous aluminium chloride is indispensable for catalyzing the Friedel-Crafts acylation of benzene rings.
• In antiperspirants: Aluminium chlorohydrate, a related compound, is common in antiperspirants, while aluminium chloride hexahydrate is used in stronger clinical-strength formulations.
  • Example: Some prescription antiperspirants contain aluminium chloride hexahydrate to control excessive sweating.

Variants and Related Words

• Aluminum chloride: The American English spelling of the compound.
• AlCl₃: The chemical formula for aluminium chloride.
• Anhydrous aluminium chloride: The water-free form, a highly reactive and hygroscopic solid.
• Aluminium chlorohydrate: A different, closely related aluminium salt used in consumer antiperspirants.

Synonyms

• Aluminum chloride (US spelling)
• Aluminum trichloride (systematic name)

Notes on Different Meanings

The term "aluminium chloride" refers specifically to the compound AlCl₃. Its primary meanings are industrial (catalyst, preservative) and chemical. Its use in personal care (antiperspirants) typically involves a hydrated form or a chemically modified relative (chlorohydrate), not the pure, anhydrous compound used in synthesis.

Noun

1. a chloride used as a wood preservative or catalyst