Appearance:
* Solid: White, deliquescent (absorbs moisture from the air) crystals.
* Liquid: Colorless, viscous liquid.
Melting Point: 192.4 °C (378 °F)
Boiling Point: 180 °C (356 °F) at 1.75 atm
Density: 2.44 g/cm³ (solid)
Solubility:
* Water: Highly soluble
* Other solvents: Soluble in ethanol, methanol, and ether.
Crystal Structure:
* Solid: Exists in two main forms:
* α-AlCl3: Layer structure with planar AlCl3 molecules held together by van der Waals forces.
* β-AlCl3: Cubic structure with AlCl4- ions in a tetrahedral arrangement.
Hygroscopicity:
* Extremely hygroscopic, readily absorbing moisture from the air to form AlCl3·6H2O (hexahydrate).
Vapor Pressure:
* Relatively high vapor pressure, especially at elevated temperatures.
Other Properties:
* Corrosive: Corrosive to metals.
* Lewis Acid: A strong Lewis acid due to the electron-deficient aluminum center.
* Sublimable: Can be sublimed under reduced pressure.
Note: These properties may vary slightly depending on the specific form (anhydrous or hydrated) and conditions (temperature, pressure) under which AlCl3 is considered.
