Aluminum sulfate is an inorganic salt commonly used as a coagulating agent in water treatment processes and as a flocculating agent in the purification of liquids.
| IUPAC Name | Aluminum sulfate |
| Molecular Formula | Al2(SO4)3 |
| CAS number | 10043-01-3 |
| Synonyms | Aluminium sulfate, dialuminum sulfate, cake alum, papermaker’s alum, filter alum |
| InChI | InChI=1S/2Al.3H2O.14H2SO4/c;;31-5(2,3)4/h;;(H2,1,2,3,4)/q2+3;/p-3 |
Aluminum Sulfate Formula
The chemical formula of aluminum sulfate is Al2(SO4)3. This formula represents the ratio of atoms in aluminum sulfate and is used to indicate the composition of the compound. The formula can also be used in chemical calculations, such as determining the molar mass or the number of moles of aluminum sulfate in a given sample. The chemical formula of aluminum sulfate is a convenient way to represent the composition of the material and is widely recognized in the scientific community. Additionally, the formula can be used to predict the chemical and physical properties of aluminum sulfate, such as its solubility in water, reactivity with other compounds, and stability under different conditions.
Aluminum Sulfate Molar Mass
The molar mass of aluminum sulfate is 342.15 g/mol. This value is important in a variety of chemical and physical calculations, including the determination of molar concentrations, reaction stoichiometry, and the ideal gas law. The molar mass is calculated by adding up the atomic weights of all the atoms in the chemical formula of aluminum sulfate, which is Al2(SO4)3. The molar mass can also be used to convert between mass and number of moles for a given sample of aluminum sulfate.
Aluminum Sulfate Boiling Point
The boiling point of aluminum sulfate is not well defined as it decomposes before boiling. Aluminum sulfate is a hydrated salt and upon heating, it loses its water of hydration and decomposes into aluminum oxide and sulfuric acid. The decomposition temperature can range from 120°C to 140°C, depending on the degree of hydration. The presence of impurities in the sample can also affect the decomposition temperature.
Aluminum Sulfate Melting Point
The melting point of aluminum sulfate is approximately 1,200°C. This high temperature is due to the strong ionic bonds between the aluminum and sulfur ions. Aluminum sulfate is a crystalline solid at room temperature and has a well-defined crystal structure, which contributes to its high melting point. The melting point of aluminum sulfate is important in determining the processing conditions required for the synthesis and purification of the material.
Aluminium Sulfate Density g/ml
The density of aluminium sulfate is 1.8 to 2.0 g/mL. This value can vary depending on the degree of hydration and the presence of impurities in the sample. The density of aluminium sulfate is an important physical property that can be used to calculate the volume of a given mass of the material. The density of aluminium sulfate is also useful in determining the concentration of a solution, as it allows for the calculation of the mass of solute per unit volume of solvent.
Aluminium Sulfate Molecular Weight
We determine the molecular weight of aluminium sulfate to be 342.15 g/mol by adding up the atomic weights of all the atoms in its chemical formula Al2(SO4)3. This value serves as both its molecular weight and molar mass and plays a crucial role in chemical calculations, including determining molar concentrations and reaction stoichiometry.
Aluminium Sulfate Structure
Aluminium sulfate possesses a crystalline structure composed of aluminium cations (Al3+) and sulfate anions (SO4^2-). The aluminium cations coordinate with six sulfate anions in a hexagonal close-packed arrangement, held together by strong ionic bonds. The crystal structure of aluminium sulfate influences its physical properties, such as melting point and solubility.
| Appearance | Crystalline Solid |
| Specific Gravity | 1.8 to 2.0 g/mL |
| Color | White |
| Odor | Odorless |
| Molar Mass | 342.15 g/mol |
| Density | 1.8 to 2.0 g/mL |
| Melting Point | 770°C |
| Boiling Point | Decomposes before boiling |
| Flash Point | Not applicable |
| Water Solubility | Soluble in water |
| Solubility | Soluble in water |
| Vapour Pressure | Not well defined |
| Vapour Density | Not well defined |
| pKa | Not well defined |
| pH | Neutral |
Aluminium Sulfate Safety and Hazards
Aluminium sulfate is a hazardous substance that must be handled with care. Inhalation of its dust can cause respiratory irritation and coughing. Contact with skin or eyes can cause redness, itching, and burning sensations. Ingestion of aluminium sulfate can cause gastrointestinal irritation, including nausea, vomiting, and diarrhea. If ingested in large amounts, it can lead to more serious health problems, such as central nervous system depression and kidney damage. Therefore, it is important to wear personal protective equipment, such as gloves and goggles, when handling aluminium sulfate. Additionally, the work area should be well-ventilated to reduce the risk of inhalation of its dust. In case of skin or eye contact, the affected area should be flushed with plenty of water for at least 15 minutes, and medical attention should be sought immediately.
| Hazard Symbols | Xi – Irritant |
| Safety Description | S24/25 – Avoid contact with skin and eyes |
| UN Ids | UN3077 – Environmental Hazard |
| HS Code | 2833.30.00 |
| Hazard Class | 8 – Corrosive Substance |
| Packing Group | III |
| Toxicity | Low to moderate toxicity if ingested, inhaled, or in contact with skin or eyes |
Aluminium Sulfate Synthesis Methods
Aluminium sulfate can be synthesized through a variety of methods, including precipitation and reaction with sulfuric acid.
One method of synthesis is the precipitation method, which involves mixing a solution of aluminium salts with sulfuric acid. This reaction results in the formation of aluminium sulfate, which precipitates out of the solution as a solid. The solid can then be filtered, washed, and dried to obtain pure aluminium sulfate.
Another method of synthesis is the reaction method, which involves mixing aluminium hydroxide or aluminium oxide with sulfuric acid. This reaction results in the formation of aluminium sulfate and water. The product can then be purified by washing and drying.
In both methods, the purity of the final product can be improved by using high-purity starting materials and by carefully controlling the conditions of the reaction. The purity of the aluminium sulfate can be verified by analyzing its physical and chemical properties, such as its molar mass, melting point, and solubility in water.
Overall, the synthesis of aluminium sulfate is a relatively straightforward process that can be performed in a laboratory or industrial setting, depending on the desired scale of production. The choice of synthesis method will depend on the availability of starting materials, desired purity of the product, and the desired scale of production.
Aluminium Sulfate Uses
Industries utilize aluminium sulfate for its versatility in various applications such as water treatment, paper production, and agriculture. In water treatment, the substance acts as a coagulant and purifies drinking water by causing impurities to aggregate and form larger particles that can be easily filtered out. The paper production industry uses aluminium sulfate as a filler and binder to improve the strength and brightness of paper and regulate pH levels in the pulp. In agriculture, aluminium sulfate lowers soil pH and increases acidity, providing essential nutrients such as sulfur and aluminium to plants. Aluminium sulfate also has additional uses, including tanning leather, fireproofing textiles, and as a flocculant in wastewater treatment. Thus, aluminium sulfate plays a significant role in modern life by serving multiple purposes across various industries.
Questions:
What is the formula for aluminum sulfate?
The chemical formula for aluminum sulfate is Al2(SO4)3.
Is aluminum sulfate soluble?
Yes, aluminum sulfate is soluble in water. It dissolves in water to form a solution of aluminum, sulfate, and hydroxide ions. The solubility of aluminum sulfate in water is temperature-dependent, meaning that it is more soluble at higher temperatures and less soluble at lower temperatures. At room temperature, aluminum sulfate is readily soluble in water, with a solubility of about 20 grams per 100 milliliters of water.