Reacts with calcium and magnesium hydrides in tetrahydrofuran forming tetrahydro aluminates, Ca(AlH4)2; reacts with hydrides of alkali metals in ether forming aluminum hydride;
Hydrolyzes in chilled, dilute HCl forming aluminum chloride hexahydrate, AlCl3⋅6H2O; reacts violently with water, evolving HCl,
AlCl3 + H2O ——› Al(OH)3 + HCl ↑
White or light-yellow crystalline solid (or amorphous solid depending on the method of production); odor of HCl; hygroscopic; melts at 190°C at 2.5 atm; sublimes at 181.2°C; density 2.44 g/cm3 at 25°C; decomposes in water evolving heat; soluble in HCl; soluble in many organic solvents, including absolute ethanol, chloroform, carbon tetrachloride and ether; slightly soluble in benzene.
Aluminum chloride reacts vigorously with water and fumes in air. It is used as a catalyst in cracking petroleum and in organic synthesis.
Aluminum chloride has extensive commercial applications. It is used primarily in the electrolytic production of aluminum. Another major use involves its catalytic applications in many organic reactions, including Friedel-Crafts alkylation, polymerization, isomerization, hydrocracking, oxidation, decarboxylation, and dehydrogenation. It is also used in the production of rare earth chlorides, electroplating of aluminum and in many metal finishing and metallurgical operations.
Contact with the skin or eyes in the presence of moisture causes thermal and acid burns.
Behavior in Fire: Reacts violently with water used in extinguishing adjacent fires
Aluminum chloride is made by chlorination of molten aluminum at temperatures between 650 to 750°C;
2 Al + 3Cl2→ 2AlCl3
or by chlorination of alumina (bauxite or clay) at 800°C in the presence of a reducing agent, such as carbon or CO. It can be prepared by similar high temperature chlorination of bauxite in the presence of a chlorinated organic reductant such as CCl4.
A pelletized mixture of clay, lignite and a small amount of NaCl is chlorinated at 900°C, producing gaseous AlCl3 (Toth process). Alternatively, alumina is mixed with about 20% by weight carbon and a small amount of sodium salt. The mixture is chlorinated at 600°C (Bayer process).
In the laboratory, anhydrous AlCl3 can be prepared by heating the metal with dry HCl gas at 150°C. The product sublimes and deposits in the cool air condenser. Unreacted HCl is vented out.
Sublime it several times in an all-glass system under nitrogen at 30-50mm pressure. It has also been sublimed in a stream of dry HCl and has been subjected to a preliminary sublimation through a section of granular aluminium metal [for manipulative details see Jensen J Am Chem Soc 79 1226 1957]. It fumes in moist air.
ALUMINUM CHLORIDE behaves as an acidic salt. Self-reactive. After long storage in closed containers, explosions often occur upon opening [Chem. Abst. 41:6723d 1947]. Can cause ethylene(also other alkenes) to polymerize violently [J. Inst. Pet. 33:254 1947]. Causes ethylene oxide to rearrange and polymerize, liberating heat [J. Soc. Chem. Ind. 68:179 1949]. Can catalyze violent polymerization of allyl chloride [Ventrone 1971]. Addition to nitrobenzene containing about 5% phenol caused a violent explosion [Chem. Eng. News 31:4915 1953]. Mixtures with nitromethane may explode when organic matter is present [Chem. Eng. News 26:2257 1948].