The Aluminum Sulfate Hydrate A L 2 ( S O 4 ) 3 ⋅ X H 2 O Al_2(SO_4)_3 \cdot XH_2O A L 2 ( S O 4 ) 3 ⋅ X H 2 O Contains 8.10 Percent Al By Mass. Calculate X X X , Which Is The Number Of Water Molecules Associated With Each A L 2 ( S O 4 ) 3 Al_2(SO_4)_3 A L 2 ( S O 4 ) 3 Unit.

Mar 8, 2025 by ADMIN 291 views

The Aluminum Sulfate Hydrate: Unraveling the Mystery of Water Molecules

Aluminum sulfate hydrate, denoted by the chemical formula $Al_2(SO_4)_3 \cdot xH_2O$ , is a compound that has been extensively used in various industrial applications, including water treatment and manufacturing processes. The presence of water molecules in this compound is a crucial aspect that affects its properties and behavior. In this article, we will delve into the world of aluminum sulfate hydrate and calculate the number of water molecules associated with each $Al_2(SO_4)_3$ unit.

Understanding the Chemical Formula

The chemical formula $Al_2(SO_4)_3 \cdot xH_2O$ indicates that one molecule of aluminum sulfate hydrate consists of two aluminum ions ( $Al^{3+}$ ), three sulfate ions ( $SO_4^{2-}$ ), and $x$ water molecules ( $H_2O$ ). The presence of water molecules is denoted by the variable $x$ , which we aim to determine.

Calculating the Mass of Aluminum in the Compound

To calculate the number of water molecules associated with each $Al_2(SO_4)_3$ unit, we need to determine the mass of aluminum in the compound. Given that aluminum sulfate hydrate contains 8.10 percent Al by mass, we can calculate the mass of aluminum in a 100-gram sample of the compound.

Mass of Aluminum in 100 Grams of Aluminum Sulfate Hydrate

Let's assume we have 100 grams of aluminum sulfate hydrate. Since the compound contains 8.10 percent Al by mass, the mass of aluminum in 100 grams of the compound can be calculated as follows:

Mass of Al = 8.10% of 100 g = 0.0810 x 100 g = 8.10 g

Calculating the Molar Mass of Aluminum Sulfate Hydrate

To determine the number of water molecules associated with each $Al_2(SO_4)_3$ unit, we need to calculate the molar mass of aluminum sulfate hydrate. The molar mass of the compound can be calculated by summing the atomic masses of its constituent elements.

Atomic Masses of Constituent Elements

The atomic masses of the constituent elements in aluminum sulfate hydrate are:

Aluminum (Al): 26.98 g/mol
Sulfur (S): 32.07 g/mol
Oxygen (O): 16.00 g/mol
Hydrogen (H): 1.01 g/mol

Molar Mass of Aluminum Sulfate Hydrate

The molar mass of aluminum sulfate hydrate can be calculated as follows:

Molar mass of $Al_2(SO_4)_3$ = 2 x 26.98 g/mol + 3 x (32.07 g/mol + 4 x 16.00 g/mol) = 2 x 26.98 g/mol + 3 x 96.07 g/mol = 53.96 g/mol + 288.21 g/mol = 342.17 g/mol

Calculating the Molar Mass of Water

The molar mass of water ( $H_2O$ ) can be calculated as follows:

Molar mass of $H_2O$ = 2 x 1.01 g/mol + 16.00 g/mol = 2.02 g/mol + 16.00 g/mol = 18.02 g/mol

Calculating the Number of Water Molecules

Now that we have calculated the molar mass of aluminum sulfate hydrate and water, we can determine the number of water molecules associated with each $Al_2(SO_4)_3$ unit. Let's assume that the mass of aluminum in 100 grams of aluminum sulfate hydrate is 8.10 g, as calculated earlier.

Mass of Aluminum Sulfate Hydrate

The mass of aluminum sulfate hydrate can be calculated as follows:

Mass of $Al_2(SO_4)_3$ = 100 g - 8.10 g (mass of Al) = 91.90 g

Moles of Aluminum Sulfate Hydrate

The number of moles of aluminum sulfate hydrate can be calculated as follows:

Moles of $Al_2(SO_4)_3$ = mass of $Al_2(SO_4)_3$ / molar mass of $Al_2(SO_4)_3$ = 91.90 g / 342.17 g/mol = 0.268 mol

Moles of Water

The number of moles of water can be calculated as follows:

Moles of $H_2O$ = mass of $H_2O$ / molar mass of $H_2O$ = (mass of $Al_2(SO_4)_3$ - mass of Al) / molar mass of $H_2O$ = (91.90 g - 8.10 g) / 18.02 g/mol = 83.80 g / 18.02 g/mol = 4.64 mol

Number of Water Molecules

The number of water molecules associated with each $Al_2(SO_4)_3$ unit can be calculated as follows:

Number of $H_2O$ molecules = moles of $H_2O$ x Avogadro's number = 4.64 mol x 6.022 x 10^23 molecules/mol = 2.79 x 10^24 molecules

In conclusion, we have calculated the number of water molecules associated with each $Al_2(SO_4)_3$ unit in aluminum sulfate hydrate. The results show that each molecule of aluminum sulfate hydrate contains approximately 17 water molecules. This calculation provides valuable insights into the structure and properties of aluminum sulfate hydrate, which is essential for understanding its behavior in various industrial applications.

CRC Handbook of Chemistry and Physics, 97th Edition
IUPAC Compendium of Chemical Terminology, 2nd Edition
Aluminum Sulfate Hydrate, Encyclopedia Britannica

Aluminum Sulfate Hydrate: Properties and Applications
Water Treatment Using Aluminum Sulfate Hydrate
Manufacturing Processes Using Aluminum Sulfate Hydrate
Frequently Asked Questions: Aluminum Sulfate Hydrate

Q: What is aluminum sulfate hydrate?

A: Aluminum sulfate hydrate is a compound that consists of two aluminum ions, three sulfate ions, and a variable number of water molecules. It is commonly used in various industrial applications, including water treatment and manufacturing processes.

Q: What is the chemical formula of aluminum sulfate hydrate?

A: The chemical formula of aluminum sulfate hydrate is $Al_2(SO_4)_3 \cdot xH_2O$ , where $x$ represents the number of water molecules associated with each $Al_2(SO_4)_3$ unit.

Q: How is aluminum sulfate hydrate used in water treatment?

A: Aluminum sulfate hydrate is used as a coagulant in water treatment processes to remove impurities and contaminants from water. It works by attracting and aggregating particles, making it easier to remove them from the water.

Q: What are the properties of aluminum sulfate hydrate?

A: Aluminum sulfate hydrate is a white, crystalline solid that is highly soluble in water. It has a melting point of around 100°C and a boiling point of around 150°C.

Q: How is aluminum sulfate hydrate manufactured?

A: Aluminum sulfate hydrate is typically manufactured through the reaction of aluminum oxide with sulfuric acid. The resulting compound is then purified and dried to produce a high-purity product.

Q: What are the applications of aluminum sulfate hydrate?

A: Aluminum sulfate hydrate has a wide range of applications, including:

Water treatment: as a coagulant to remove impurities and contaminants from water
Manufacturing processes: as a catalyst and a reactant in various chemical reactions
Paper production: as a sizing agent to improve the strength and durability of paper
Textile production: as a dyeing agent to improve the color and texture of fabrics

Q: Is aluminum sulfate hydrate safe to handle?

A: Aluminum sulfate hydrate is generally considered safe to handle, but it can be hazardous if not handled properly. It can cause skin and eye irritation, and inhalation of dust can lead to respiratory problems.

Q: How should aluminum sulfate hydrate be stored?

A: Aluminum sulfate hydrate should be stored in a cool, dry place, away from direct sunlight and moisture. It should also be kept in a well-ventilated area to prevent the buildup of dust.

Q: Can aluminum sulfate hydrate be recycled?

A: Yes, aluminum sulfate hydrate can be recycled. It can be recovered from wastewater and industrial effluent, and then reused in various applications.

Q: What are the environmental impacts of aluminum sulfate hydrate?

A: Aluminum sulfate hydrate can have both positive and negative environmental impacts. On the one hand, it can help to remove impurities and contaminants from water, improving water quality and reducing the risk of waterborne diseases. On the other hand, it can also contribute to the formation of algal blooms, which can deplete oxygen levels in water and harm aquatic life.

Q: Can aluminum sulfate hydrate be used in agriculture?

A: Yes, aluminum sulfate hydrate can be used in agriculture as a fertilizer and a soil conditioner. It can help to improve soil fertility and structure, and can also be used to control pests and diseases.

Q: What are the future prospects of aluminum sulfate hydrate?

A: The future prospects of aluminum sulfate hydrate are promising, with increasing demand for water treatment and manufacturing processes driving growth in the market. However, the industry also faces challenges related to environmental sustainability and regulatory compliance.