Chemical Properties of AlCl3

AlCl3 is an anhydrous, white salt ( white when the pure presence of contaminants such as iron chloride gives it a yellowish colour) compound formed by the reaction of chlorine and aluminium solutions. The reaction is exothermic. It contains one aluminium atom and three chlorine atoms. AlCl3 chemical properties, structure formation, and uses are necessary to understand chlorides of Period 3 Elements. AlCl3 can be recognized as a catalyst for organic reactions through its chemical properties. The electronegativity difference between aluminium and chlorine is insufficient for simple ionic bond formation. It is unstable and changes with temperature.

Structure of AlCl3

The evaporation density of anhydrous aluminium chloride is 133 at 400 degrees Celsius. Based on this, its formula is Al2Cl6. Chlorine forms a tetrahedral shape, with Al at the centre. In the structure of this formula, three chlorine atoms are bound to one aluminium atom, co-conjugated, and a cohesive bond binds one chlorine atom.

At 800 degrees Celsius, Al2Cl6 becomes AlCl3 because, with an increase in heat, the vapour density of anhydrous aluminium chloride decreases. Anhydrous aluminium chloride can merge with organic solvents like ether, carbon tetrachloride, alcohol, and acetone because of cohesive bonds. It is a non-conductor of electricity in a molten state.

Properties of Aluminium Chloride

Chemical Properties Of Aluminium Chloride

• It is non-explosive, non-flammable, anhydrous.
• In its solid form, aluminium chloride salt is corrosive.
• It is a powerful Lewis acid.
• Acts as an industrial catalyst.

Reaction with water

When exposed to moisture or mixed with water, aluminium chloride forms an aqueous solution. It causes water decomposition. 

AlCl3 + 3H2O ⇌ Al(OH)3 + 3HCl

Because of the decomposition of water, the aqueous solution is acidic in nature. The reaction of aluminium chloride with water portrays its decomposition properties and acidic chemical properties. Hydrogen chloride or HCl is formed when aluminium chloride is exposed to moisture. A cloud of white smoke is observed when HCl is formed.

Aluminium chloride crystals are obtained by evaporating their aqueous solution.

AlCl3 + 6H2O → AlCl3.6H2O

The Reaction Of Aluminium Chloride And Dilute NH4OH Solution:

The reaction of aluminium chloride with dilute NH4OH solution gives a precipitate aluminium hydroxide. The precipitate is white in colour.

AlCl3 + 3NH4OH → 3NH4Cl + Al(OH)3

This reaction escalates and gives alumina (Al2O3) when heated.

2Al(OH)3 → Al2O3 + 3H2O

Aluminium sulphate is formed when dissolved with H2SO4.

2Al(OH)3 + 3H2SO4 → Al2(SO4)3 + 3H2O

The Reaction Of Aluminium Chloride With Caustic Soda (Naoh):

The reaction between aluminium chloride solution and caustic soda produces aluminium hydroxide precipitate. 

AlCl3 + 3NaOH → 3NaCl + Al(OH)3

The precipitate dissolves in excess caustic soda, forming sodium metal aluminate.

Al(OH)3 + NaOH → 2H2O + NaAlO2

Ammonia Absorption:

AlCl3 chemical properties show that it can make ammonia edited by absorbing it.

AlCl3 + 6NH3 → AlCl3.6NH

Aluminium Chloride Preparation

Chemical preparation methods at a temperature range of 650 degrees Celsius to 750 degrees Celsius are;

• The reaction of hydrochloric acid and aluminium metal: It is an exothermic reaction.

2Al + 3Cl2→ 2AlCl3

• The reaction of aluminium metal and chlorine: When aluminium reacts with hydrochloric acid, it forms aluminium chloride;

2Al + 6HCl → 2AlCl3 + 3H2

When an aluminium metal reacts with copper chloride, it forms aluminium chloride. It is a single displacement reaction;

2Al + 3CuCl2 → 2AlCl3 + 3Cu

Chemical Uses Of Aluminium Chloride

Aluminium chloride AlCl3 chemical properties importance are useful in two broad areas;

Acylation and Alkylation of arenas: 

The equipment and aluminium chloride should be dry for using AlCl3 chemical properties through both of these reactions. Any trace of moisture is hazardous. In the production process, zeolites can replace aluminium chloride because, in the Friedel-Crafts reaction, the aluminium chloride catalyst generates corrosive wastes. This is because it is required in full stoichiometric quantities due to its strong complexes with products.

It is also used for introducing aldehyde groups into aromatic rings.

Organic and Organometallic synthesis applications: 

This is an application of AlCl3 chemical properties in organic chemistry. Hydrocarbon couplings and rearrangements are induced with AlCl3. AlCl3 is used to synthesise bis(arene) metal complexes when combined with aluminium, in the presence of an arene.

Industrial use of aluminium chloride

• Serving as a catalyst in Friedel crafts reactions.
• For cotton lubricant and cotton spinning.
• Used to make detergents.
• Can purify mineral oils.
• Acts as a paint bond in printing, and dyeing. Liquid aluminium chloride is used for paints.
• MgO and AlCl3 mixture is used to make floors, teeth fittings, and fix broken clay pots.

Conclusion

Aluminium chloride is a chemical compound that is made up of inorganic elements. AlCl3 is the chemical formula for aluminium chloride. It has a hygroscopic property. As a result, it has a stronger attraction for water. It can also be found as a dimer. 

We looked at the chemical properties and the uses of AlCl3. AlCl3 can be recognized as a catalyst for organic reactions through its chemical properties. The electronegativity difference between aluminium and chlorine is insufficient for simple ionic bond formation. The chemical properties of AlCl3 are extensively looked into in terms of chemical industries.It can be used in a variety of ways. It is a catalyst in various organic processes and has also been used in organometallic synthesis.