Aluminium Hydroxide Formula, Structure, Method, Equation

Aluminium Hydroxide Formula is a chemical compound that finds applications in various industries, especially in pharmaceuticals and antacid preparations. An amorphous white powder, Aluminium Hydroxide is present in nature. Gibbsite is a mineral that occurs naturally (also known as hydrargillite).

Ayerite, doyleite, and nordstrandite are other polymorphs of Aluminium Hydroxide. It is an amphoteric oxide with a molar mass of 78.00 g/mol.

As a filler with fire-retardant properties, aluminium hydroxide can also be used in polymer applications. Magnesium Hydroxide, combined with Huntite and Hydromagnesite, is also used for these applications. Magnesium Hydroxide has excellent fire-retardant properties, is inexpensive, and is colourless (like other polymers).

Decomposition occurs around 180 °C (356 °F), during which it absorbs a significant amount of heat and releases water vapour. In addition to being a fire retardant, it also works incredibly well as a smoke suppressant in various polymers, such as rubber, polyester, acrylics, ethylene vinyl acetate, epoxies, and PVC.

Structure Formula of Aluminium Hydroxide

Aluminium ions fill two-thirds of the octahedral holes in Al(OH) ₃ between two layers of hydroxyl groups. There have been four polymorphs identified. All of them contain layers of octahedral aluminium hydroxide units linked by hydrogen bonds. The layers are stacked differently in each polymorph. In all forms, Al(OH) ₃ crystals are hexagonal.

Aluminium Hydroxide Formula by Criss Cross Method

The chemical formula of aluminium hydroxide Al(OH) ₃ can be determined using the criss-cross method, which involves balancing the charges of the constituent ions. Aluminium has a +3 charge Al(OH) ₃ , while hydroxide ions carry a -1 charge. To balance the charges, you simply cross over the numerical values, resulting in Al(OH) ₃ as the chemical formula.

Aluminium Hydroxide Equation

The chemical equation for the formation of aluminium hydroxide can be represented as follows:

\[Al^{3+} + 3OH ^- → Al(OH)_3\]

This equation illustrates how aluminium ions (\(Al^{3+}\)) combine with three hydroxide ions (\(OH^-\)) to form aluminium hydroxide Al(OH) ₃

Aluminium Hydroxide Equation for Acid

Aluminium hydroxide is amphoteric, which can react with acids and bases. In the presence of an acid, it can neutralise the acid, producing water and salt. For example, when reacting with hydrochloric acid HCl, the equation is:

Al(OH)3 + 3HCl 3H2O + AlCl3

This reaction results in the formation of water (H ₂ O) and aluminium chloride. AlCl3

Aluminium Hydroxide Gel Formula

Aluminium hydroxide gel is a common formulation used in antacids. It consists of the same chemical formula, Al(OH) ₃ but it is often prepared in a gel form for ease of administration and better dispersion in the stomach.

Aluminium Hydroxide Gel Formulation

The formulation of aluminium hydroxide gel typically involves dispersing finely ground aluminium hydroxide in a suitable gel-forming base, often containing substances like magnesium hydroxide, calcium carbonate, or simethicone. These formulations are designed to provide relief from symptoms of indigestion and heartburn.

Aluminium Hydroxide Chloride Formula

Aluminium hydroxide chloride is not a commonly recognized chemical compound. It's possible that the name is a mixture or complex of aluminium hydroxide and aluminium chloride, and its formula would depend on the specific composition.

Aluminium Sodium Hydroxide Formula

Aluminium sodium hydroxide is also not a standard chemical compound. The formula would depend on the specific composition and the ratio of the elements present.

Aluminium Ammonium Hydroxide Formula

Like the previous examples, Aluminium ammonium hydroxide is not a standard compound with a fixed chemical formula. The formula would vary based on the composition and ratios of aluminium, ammonium, and hydroxide ions.

Production of Aluminium Hydroxide

The Bayer method, a process which involves dissolving bauxite in sodium hydroxide at high temperatures, is responsible for the majority of commercially used aluminium hydroxide. Once the bauxite tailings are removed, the remaining solution, known as sodium aluminate, can be used to precipitate aluminium hydroxide. This substance can then be calcined to produce aluminium oxide or alumina. However, the residue left behind, primarily iron oxide and leftover sodium hydroxide, can be highly corrosive. This caustic byproduct was previously stored in lagoons at the Ajka alumina factory in Hungary, ultimately resulting in a tragic incident in 2010 when a dam collapsed and caused widespread damage and chemical burns. Although deemed non-toxic due to low levels of heavy metals, the slurry mixed with it had an incredibly high pH level of 13.

Amphoteric Aluminium Hydroxide Formula

Amphoteric aluminium hydroxide, which refers to the compound's ability to react with both acids and bases, retains the chemical formula Al(OH)3. This formula represents the fundamental composition of aluminium hydroxide and its amphoterism.