Need Help?

Get in touch with us


Aluminium Hydroxide Al(OH)4- Structure, Molecular mass, Properties, Uses

Jan 25, 2023

The majority are aware that while aluminium oxide is an antacid, aluminium itself is a naturally occurring mineral. It treats stomach discomfort, acid indigestion, heartburn, and sour stomach. In addition, you may use it to lower phosphate levels in renal disease patients. Other non-medical uses for the antacid may be possible.

What is Aluminium Hydroxide?

For those who do not know what aluminium hydroxide is, it is also known as Aluminium Hydroxide, Aluminium (III) Hydroxide, or Aluminic Acid. It is the same as all existing other metal carbonates, sulphates, and hydroxides and is the chemical term for aluminium. It is naturally occurring as the mineral and its polymorph, which is known as bayerite.


Aluminium Hydroxide Formula 

Al(OH)3  is its formula. The amorphous white powder is aluminium hydroxide. It is insoluble in water. However, it is soluble in solutions that are alkaline and acidic. It is beneficial for treating stomach pain, heartburn, acid indigestion, and sour stomach.

In addition, it can help those with kidney problems reduce their phosphate levels. The antacid could also be helpful outside of medicine. It is present in the mineral ores of gibbsites, bayertute, doyleite, and strandite, just as other metals’ carbonates, hydroxides, and sulphates.


Aluminium Hydroxide’s Structure 

It may act as an acid and a base, depending upon the compound with which it is reacting. It manifests as the hydroxide ion, OH-, and the aluminium ion,Al3+, in acidic solutions.Al(OH)4, an ion of aluminium hydroxide, is one example of how it appears in basic solutions.

The tetrahedral structure of this ion has a bond angle of 116.5°, which is formed between aluminium and oxygen atoms. The typical structure includes hydrogen bonds. It consists of aluminium ions’ two layers and hydroxyl groups’ two layers, which occupy two-thirds of the octahedral formations between the two layers.


The amphoteric mineral gibbsite acts as a Bronsted-Lowry base by collecting hydrogen ions and neutralizing the acid to generate salt.

3HCl (aq) + Al(OH)3 -> AlCl3 (aq) + 3H2O (l)


It behaves as a Lewis acid in bases. It weakens an electron pair’s hydroxide ions. One more reaction is

Al(OH)3 + OH -> Al(OH)4


Aluminium Hydroxide Preparation 

Producing this for use in an industry requires the Bayer process. Bauxite is dissolved in a sodium hydroxide solution at temperatures between 0 and 270 °C to achieve this. After eliminating the garbage, the solution of sodium aluminate is allowed to precipitate. Due to this, it is the precipitation.

It can be calcined to yield alumina or aluminium oxide.


Bayer Process Reactions

Al2O3.2H2O + 2NaOH -> 2NaAlO2 + 3H2O


 NaAlO2 + 2H2O -> Al(OH)3 + NaOH

2Al(OH)3 -> Al2O3 + 3H2O

Precautions to Take During the Production of Aluminium Hydroxide Gel

  1. By boiling it in hot water, the person making the preparation must clean the conical flask to remove any dirt or bacteria.
  2. The degradation of the restored gel causes the reaction to produce the by-product, hydrochloric acid. The dialysis procedure is thus required to eliminate it.
  3. The aluminium chloride solutions need to include a downward spiral. 

The Making of Aluminium Hydroxide Gel

  1. At a minimum of 2%, it is necessary to make the aluminium chloride solution(by adding 2 g of aluminium chloride to 100 ml of water).
  2. At least 100ml of distilled water must be present in the conical flask.
  3. To boil water, use wire gauze.
  4. Add 10 mL of the 2% aluminium chloride solution produced above. Using a burette dropper, add this solution. Composites have a violent nature by nature, like aluminium.
  5. Add aluminium chloride to the solution and shake regularly.
  6. While heating the solution, the color of this solution changes to white.
  7. Keep the mixture at room temperature until cool.
  8. This gel is the cooling solution.

Aluminium Hydroxide’s Physical Characteristics

The following are its physical features. The amorphous white powder is aluminium hydroxide.

  1. The melting point is about 573K.
  2. Alkalis and acids make it soluble, but not in water.
  3. The density of the solid is 2.42g/cm3 approx.

Aluminium Hydroxide’s Chemical Characteristics

  1. The amorphous material is aluminium hydroxide.
  2. It may act as a base as well as an acid.
  3. In acids, aluminium hydroxide exhibits Bronsted-Lowry base behavior.
  4. As a result, it balances the final products, which are acid-producing salt and water.

Uses of Aluminium Hydroxide 

Numerous advantages come with this, including massive production, ample raw materials, superb product quality, and superior acid solubility. 

  1. It is a crucial raw material for producing aluminium salts such as barium aluminate, aluminium sulphate, and others.
  2. Aluminium hydroxide powder is well known as a good flame retardant filler for plastics, rubber, unsaturated polyester, and numerous organic polymers due to its filling, flame retardant, smoke-eliminating, and non-toxic qualities. The mechanism of this as a flame retardant is as follows: at temperatures over 200 °C, aluminium hydroxide starts to hold an endothermic breakdown and separates three crystals of water. At 250°C, the rate of decomposition reaches its maximum.
  3. Alumina, a substance with strong creep resistance, thermal strength, thermal chemical stability, dielectric properties, and a low thermal expansion coefficient, may be produced from this. An essential component in the creation of ceramics is alumina.
  4. By activating this and controlling the crystallization process, we may control the development phase of the composite during the ceramic synthesis process.
  5. Al(OH)4-, the main form of aluminium hydroxide in water, can precipitate dangerous heavy metals in sewage using the coprecipitation method to purify water after further filtration. This may adsorb colloids, suspended particles, pigments, and organic substances from sewage due to its high specific surface area.
  6. It is frequently used as a traditional medicine for stomach treatment because of its non-toxic nature and capacity to neutralize gastric acid.
  7. The adjuvant aluminium hydroxide can potentially increase the vaccine’s immunogenicity. The mechanism of action is as follows: It absorbs antigen on its surface, allowing the antigen to be released gradually and extending efficacy.
  8. For the purpose of producing a range of target products with different surface areas, pore volumes, pore structures, and crystal structures that have a use as catalyst carriers for the unsaturated carbonyl compounds hydrogenation and the production of fullerenes and other related compounds, we must manage the temperature, concentration, and pH of the reactants.
  9. It is compatible with brighteners because of its excellent whiteness, complete crystal structure, and ultrafine particle size.  A second coating and resin made of this may significantly improve coated paper’s whiteness, smooth texture, opacity, and ink absorption.

Aluminium hydroxide’s function

Aluminium is a metal that occurs naturally. The antihistamine is aluminium hydroxide. Acid indigestion, pain in the stomach, heartburn, and stomach discomfort are all treated with this. It lowers phosphate levels in patients with various renal diseases.

Effects of Aluminium Hydroxide

Users of aluminium hydroxide need to be aware of several significant side effects. A lot of health harm can result from high amounts of the same substance. It may cause lung damage, hives, trouble breathing, and allergic reactions such as swollen tongue, lips, throat, and face. An additional negative impact of utilizing aluminium hydroxide:

  1. Having difficulty urinating.
  2. Severe stomach ache or constipation.
  3. Hunger loss.
  4. Fatigue and weakened muscles.
  5. Bloody or sticky stools.
  6. Spitting up blood. 
  7. Coughing.
  8. Extreme mental fogginess.

Get immediate emergency assistance if you notice any of these adverse effects. Better still, get advice from a medical practitioner before ingesting any products that contain significant amounts of the mineral.


Aluminium Hydroxide reacts with both bases and acids.TiO2 nanoparticles have an aluminium hydroxide coating. In patients with specific renal problems, aluminium oxide lowers phosphate levels. Utilising aluminium oxide inhibits the body’s absorption of other substances. For future usage in this respect, the two-hour intervals before and after taking aluminium hydroxide is necessary.

Frequently Answers Questions on Aluminium Hydroxide 

1.What is aluminium hydroxide’s chemical composition?

A:Al(OH)3 is the chemical formula for aluminium oxide. The aluminium cation,Al3+, and three hydroxyl anions,

CO3-2, are used to make the molecule. Because the ions tend to have different configurations, the structure of aluminium oxide depends on the extract from the material. Orthorhombic or hexagonal lattices make up the bulk of mineral structures.

Bauxite is mixed with and dissolved in hydroxide solution at a temperature of up to 270 degrees Celsius to create the chemical formula for aluminium oxide. In close relation to aluminium oxide hydroxide, aluminium hydroxide possesses both basic and acidic characteristics.

2.What exactly is aluminium oxide gel?

A:The amorphous aluminium hydroxide suspension is known as aluminium hydroxide gel. The mineral’s gel form contains partial replacements for carbon. Along with several other tastes, the gel may also include peppermint oil, glycerine, sorbitol, sucrose, and saccharin. Additionally, the gel may have the right proportions of several antibacterial substances.

Heartburn, acid indigestion, and stomach discomfort are among the disorders treated with it most frequently. Compared to pills or capsules, it works better. The gel is created by precipitating the ethanolic aluminium chloride solutions. Additionally included are primary amines such as dodecylamine, propylamine, and octylamine. These act as proton acceptors, allowing precipitation to occur during hydrolysis.

3.Are bases made of alkali hydroxide weak?

A:Aluminium hydroxide is a chemical compound with the molecular formula Al(OH)3. When hydroxide (OH) in aluminium hydroxide interacts with hydrochloric acid, a strong acid, it can serve as a weak base (HCl). A weak base is one that breaks apart in solution or partly dissociates.

Aluminium Hydroxide


Relevant Articles

Butanoic Acid

Butanoic Acid – Structure, Properties, Uses

Butanoic Acid The carboxylic acid, butanoic acid, has the structural …

Butanoic Acid – Structure, Properties, Uses Read More »


What is Iodoform? Characteristics and Uses

Iodoform The formula for Iodoform is CHI3. It is biotic …

What is Iodoform? Characteristics and Uses Read More »

Lattice Energy

Lattice Energy – Explanation, Factors & Formulas

Lattice Energy Lattice energy evaluates the intensity of the ionic …

Lattice Energy – Explanation, Factors & Formulas Read More »

Lead Acetate

Lead Acetate – Definition, Properties, Uses

Lead Acetate Have you ever licked lipstick when you sketch …

Lead Acetate – Definition, Properties, Uses Read More »


Study Abroad

card img

With Turito Study Abroad

card img

With Turito Study Abroad

card img

Get an Expert Advice from Turito

card img

Get an Expert Advice from Turito


card img

With Turito CAP.


card img

With Turito Coding.


card img

With Turito RoboNinja


card img

1-on-1 tutoring for the undivided attention