Aluminum Chloride Hexahydrate: Properties, Uses, and Industrial Importance

Aluminum chloride hexahydrate (AlCl₃·6H₂O) is a hydrated form of aluminum chloride, widely used in chemical synthesis, water treatment, and personal care products. Its versatility, solubility in water, and Lewis acid character make it an essential chemical in various industries.

What is Aluminum Chloride Hexahydrate?

Chemical formula: AlCl₃·6H₂O
Molar mass: 241.43 g/mol
Appearance: White to yellowish crystalline solid
Odor: Slight acidic odor
Solubility: Highly soluble in water, alcohol, and acetone
CAS Number: 7784-13-6

Aluminum chloride hexahydrate is the hydrated crystalline form of aluminum chloride, meaning it contains six water molecules per aluminum chloride unit. It is more stable and easier to handle than anhydrous aluminum chloride, which is extremely hygroscopic and fuming.

Physical and Chemical Properties

Property	Value
Appearance	Colorless to white crystals
Melting Point	~100 °C (with decomposition)
pH (in solution)	~2–3 (acidic)
Density	~2.398 g/cm³
Solubility	Very soluble in water
Stability	Stable in dry air; decomposes in moist air over time

Applications of Aluminum Chloride Hexahydrate

1. Water and Wastewater Treatment

Used as a coagulant and flocculant to remove suspended solids, heavy metals, and organic matter from water.
Helps clarify drinking water, industrial wastewater, and municipal sewage.

2. Pharmaceuticals and Dermatology

Active ingredient in antiperspirants and deodorants.
Reduces sweating by blocking sweat glands.
Used in dermatological treatments for hyperhidrosis (excessive sweating).

3. Organic Synthesis and Catalysis

Serves as a mild Lewis acid in organic reactions such as:
- Friedel–Crafts alkylation and acylation
- Polymerization of olefins
The hydrated form is less reactive but more manageable for laboratory and industrial reactions.

4. Textile and Dye Industry

Acts as a mordant (fixative) to bind dyes to fabrics.
Enhances color fastness and improves appearance of dyed materials.

5. Paper and Pulp Processing

Used to precipitate rosin, aiding in the sizing of paper and improving printability and texture.

Handling and Safety

Safety Considerations:

Corrosive to eyes, skin, and mucous membranes.
Releases hydrochloric acid fumes when heated.
Use gloves, goggles, and lab coat when handling.
Store in sealed containers away from moisture and bases.

First Aid

Skin contact: Rinse with soap and water.
Eye contact: Flush with water for at least 15 minutes.
Inhalation: Move to fresh air; seek medical attention if symptoms persist.

Environmental Impact

Aluminum chloride hexahydrate should not be released directly into natural water sources, as it can alter pH and aluminum levels, potentially harming aquatic ecosystems. Waste solutions should be neutralized and disposed of according to local environmental regulations.

Comparison: Hydrated vs Anhydrous Aluminum Chloride

Property	Hydrated (AlCl₃·6H₂O)	Anhydrous (AlCl₃)
Form	Crystalline solid	White/yellow powder
Reactivity	Mild Lewis acid	Strong Lewis acid
Fumes in air	No	Yes (releases HCl gas)
Stability	More stable	Highly reactive
Applications	Skincare, water treatment, mild catalysis	Strong catalysis, chlorination

Conclusion

Aluminum chloride hexahydrate is a versatile, stable, and highly functional compound with critical roles in water purification, pharmaceuticals, chemical synthesis, and material processing. Its hydrated form offers safe handling and effective performance across a wide range of applications. With appropriate safety measures, it remains an indispensable tool in both commercial and scientific settings.

Keywords: aluminum chloride hexahydrate, AlCl₃·6H₂O, water treatment chemical, antiperspirant active, Lewis acid catalyst, aluminum salt, coagulant

Contact Us

Phone : +49 1512 4714765 ( Germany )
Phone : +1 (702) 381-3042 ( USA )
Email : [email protected]
Address : Cunostraße 56, 14193 Berlin. Germany
Address : 7373 Rowlett Park Dr, Tampa, FL 33610, United States.

Blog