How Is Aluminium Chloride Hexahydrate Synthesized?

Aluminium chloride hexahydrate is synthesized by dissolving aluminium oxide or hydroxide in hydrochloric acid and subsequently evaporating the resulting solution under controlled conditions to obtain the desired crystalline product.

Here are the steps involved in the synthesis of aluminium chloride hexahydrate:

1. Dissolving aluminium oxide or hydroxide: Aluminium oxide or hydroxide is first dissolved in hydrochloric acid. The reaction can be represented by the following equation:

Al2O3 + 6HCl → 2AlCl3 + 3H2O

2. Evaporation: The resulting solution is then evaporated under controlled conditions, such as temperature and pressure, to promote the formation of aluminium chloride hexahydrate crystals. The evaporation process removes excess water and concentrates the solution, resulting in the precipitation of the desired product.

3. Filtration and drying: Once the crystals have formed, they are filtered out of the remaining solution and washed with a suitable solvent to remove any impurities. Finally, the crystals are dried to remove any remaining moisture.

The resulting product is a white crystalline solid with the chemical formula AlCl3.6H2O, which indicates that it contains six molecules of water per molecule of aluminium chloride. It is commonly used as a Lewis acid catalyst in organic synthesis reactions and as a coagulant in water treatment processes.