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Aluminium Chloride

Hans Christian Oersted, a Danish physicist and chemist who worked in the field of chemistry, made the first discovery of aluminium chloride in the year 1825. This chemical compound is one of the oldest chemicals still in use today, and it is particularly prevalent in the field of organic chemistry.

Uses of Aluminium Chloride (AlCl3)

Aluminium chloride is also referred to as aluminium trichloride or aluminium (III) chloride in some circles. When aluminium and chlorine react with one another, the compound is formed as a result. AlCl3 is the chemical formula for this compound. Aluminium chloride is typically white in colour when it comes to its physical appearance. However, because of the presence of contaminants (iron(III) chloride), it takes on a yellowish hue.

Besides being used in the production of aluminium metal, aluminium chloride has a wide range of applications in the chemical industry, particularly as a Lewis acid, which is discussed further below. With a low melting and boiling point, solid aluminium chloride (AlCl3) is covalently bonded and has a low melting point.

Aluminium Chloride is the chemical compound designated by the International Union of Pure and Applied Chemistry (IUPAC).

Various other names :- 

Aluminium(III) Chloride, Aluminium Trichloride 

Formula for a chemical compound :AlCl3

  1. Mass of a molecule 133.341 g/mol (anhydrous)
  2. the atomic weight of 241.432 g/mol (hexahydrate)
  3. Density : 2.48 g/cm3 is the density of air in a cubic centimetre (anhydrous)            2.398 g/cm3 is the density in grammes per cubic centimetre   (hexahydrate)
  4. The melting point is 192.6 degrees Celsius (anhydrous)  100°C is the maximum temperature (hexahydrate, dec.)
  5. 180 degrees Celsius is the boiling point.
  6. Solubility in Water is a measure of how well something dissolves in water.
    • 439 g/l (at 0 degrees Celsius)
    • 449 g/l (at 10 degrees Celsius)
    • 458 g/l (at 20 degrees Celsius)
    • 466 g/l (at 30 degrees Celsius)
    • 473 g/l (at 40 degrees Celsius)
    • 481 g/l (at 60 degrees Celsius)
    • 486 g/l (at 80 degrees Celsius)
  • 490 g/l (at 100 degrees Celsius)

    7.Vapour pressure: 133.3 Pa (99 degrees Celsius).  13.3 kPa (151 degrees Celsius)

    8.Viscosity 0.35 cP (197 degrees Celsius) 0.26 cP (237 degrees Celsius)

Preparation 

Aluminium Chloride is made in a laboratory.

An exothermic reaction between two elements, namely aluminium and chlorine, is the primary method by which aluminium chloride is produced. Obtaining aluminium chloride can be accomplished through a variety of other methods.

Examples include reacting aluminium metal with hydrogen chloride or conducting a single displacement reaction between copper chloride and aluminium metal, both of which are common methods. The following are examples of reactions to the same:

2Al + 3Cl2 2AlCl3 is a chemical reaction.

2Al + 6HCl — 2Al 6HCl 2AlCl3 + H2 = 2AlCl3 + H2

In the reaction of 2Al + 3CuCl2 to form 2AlCl3 + 3Cu

Aluminium Chloride Crystallisation

When we talk about the structure of AlCl3, we can get a little lost in the details. When exposed to different temperatures, this chemical compound has a tendency to form a variety of different types of structures. It also depends on the state of the compound, which can be solid, liquid, or gaseous depending on the situation. Aluminium Chloride is a chemical compound that is used to make aluminium (AlCl3)

Aluminium Chloride (AlCl3) components 

During the solid-state phase of AlCl3, the structure is a cubic close-packed layered structure. In this case, the coordination geometry of the system will be octahedral in nature. When aluminium chloride is in a liquid or molten state, it exists as a dimer, which is a compound compound compound. Its coordination geometry will be tetrahedral in this case. Upon heating to a higher temperature, the dimers dissociate into trigonal planar atoms.

Characteristics of Aluminium Chloride

Physical properties:

The melting and boiling points of aluminium chloride are extremely low.

It reaches its zenith at 180 degrees Celsius.

AlCl3 is a poor conductor of electricity when it is in a molten state.

Aluminium chloride is white in colour, but it is frequently contaminated with iron trichloride, which causes it to become yellow in colour.

It is only in a liquid state at pressures greater than 2.5 atm and temperatures greater than 190°C.

Chemical properties:

Aluminium chloride is a potent Lewis acid with a wide pH range.

It serves as a significant industrial catalyst.

AlCl3 is a solid that is anhydrous, non-explosive, and non-flammable, but it is also corrosive.

This substance reacts violently when it comes into contact with water or acids.

Reactions with Aluminium Chloride

We will learn about AlCl3’s interactions with other compounds in this section. When we take anhydrous aluminium chloride, we have a very powerful Lewis acid on our hands. This means that it is capable of forming Lewis acid-base adducts even with bases that are weak in nature, which is a significant advantage. For instance, mesitylene and benzophenone are two such chemicals. Some of the most common reactions are as follows:

When chloride ions are present, AlCl3 can react with oxygen to form tetrachloroaluminate (AlCl-4).

Tetrahydrofuran can be used to create tetrahydridoaluminate, which is formed when aluminium chloride reacts with magnesium and calcium hydroxide.

Aluminium Chloride Reaction with Water Aluminium chloride is considered to be hygroscopic, which means that it can absorb moisture from the air when exposed to it. Normally, this chemical compound emits fumes into moist air, indicating that it is toxic. When this product comes into contact with water, it produces a hissing sound. When the reaction takes place, the Cl– ions are replaced by H2O molecules, resulting in the formation of hexahydrate [Al(H2O)6]Cl3. The anhydrous state of AlCl3 is lost, and when heat is applied, the HCl dissipates as well, resulting in the formation of aluminium hydroxide as the end result of the reaction.

Al(OH)3 + 3HCl + 3H2O —> Al(OH)3 + 3HCl + 3H2O

After increasing the temperature to approximately 400°C, aluminium oxide is formed by the reaction of the hydroxide with the oxygen.

Al(OH)3 + 3H2O —> 2Al(OH)3 + 3H2O

The fact that AlCl3 aqueous solutions are ionic is one of their distinguishing characteristics. As a result of this, they are excellent conductors of electricity. They are also acidic, which can result in partial hydrolysis of the Al3+ ion in some cases. The following is an example of how to express the reaction:

[Al(H2O)6]

3+(aq) —> 3+(aq) [Al(OH)(H2O)5] 2+(aq) + H+ —>2+(aq) + H+ (aq)

Aluminium salts containing the hydrated Al3+ ion are chemically similar to aqueous solutions of aluminium chloride in their properties. They also behave in a similar manner. When it is reacted with dilute sodium hydroxide, for example, it produces a thick precipitate of Al(OH)3.

Precautions to be taken with Aluminium Chloride (AlCl3) 

It is important to keep anhydrous aluminium chloride away from water and bases to avoid potential contamination. Because of the high heat generated during hydration, aluminium chloride can explode if it comes into contact with water. It also emits fumes into the atmosphere. During chemical reactions, protective equipment such as safety glasses, gloves, face guards, and other similar items should be worn. This chemical compound should be stored in a container with a tight-fitting lid and away from moisture.

When AlCl3 comes into contact with moist air, it can absorb the moisture present in the air, causing it to become highly acidic and transforming it into a sticky substance. AlCl3 can also absorb moisture from water vapour.

It has the ability to corrode materials such as stainless steel and rubber at a rapid rate.

Skin, eyes, and respiratory tract irritation are all possible side effects of prolonged exposure to this chemical.

Aluminium chloride has been discovered in some studies to be a neurotoxin, meaning that it can be toxic to nerve tissues and cause permanent damage.

Conclusion 

Therefore we can conclude that, Aluminium chloride is also referred to as aluminium trichloride or aluminium (III) chloride in some circles. When aluminium and chlorine react with one another, the compound is formed as a result. AlCl3 is the chemical formula for this compound. Aluminium chloride is typically white in colour when it comes to its physical appearance. However, because of the presence of contaminants (iron(III) chloride), it takes on a yellowish hue.

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