The Importance of Oxygen Atoms in Scheelite

Oct 13, 2025 by miodeya.com 14 views

Understanding Scheelite and Its Composition

Scheelite, chemically represented as CaWO4, is a mineral composed of calcium, tungsten, and oxygen. It is a significant source of tungsten, a hard, dense, gray-white to gray-blue transition metal that is highly valued for its high melting point, high density, and ability to withstand extremely high temperatures. The chemical formula of scheelite indicates that it contains one calcium atom, one tungsten atom, and four oxygen atoms per formula unit.

The Importance of Oxygen Atoms in Scheelite

Oxygen atoms play a crucial role in the structure and properties of scheelite. They form a tetrahedral arrangement around the tungsten atom, which is essential for the mineral's stability and its ability to exhibit unique optical and electrical properties. In this article, we will focus on calculating the mass of scheelite that contains a billion oxygen atoms.

Calculating the Number of Formula Units

To calculate the mass of scheelite, we first need to determine the number of formula units present in the given amount of oxygen atoms. Since each formula unit of scheelite contains four oxygen atoms, we can calculate the number of formula units as follows:

Number of formula units = Total number of oxygen atoms / Number of oxygen atoms per formula unit = 1.0 x 10^9 / 4 = 2.5 x 10^8 formula units

Calculating the Mass of Scheelite

Now that we have the number of formula units, we can calculate the mass of scheelite using the atomic masses of calcium, tungsten, and oxygen. The atomic masses of these elements are:

Calcium (Ca): 40.08 g/mol
Tungsten (W): 183.84 g/mol
Oxygen (O): 16.00 g/mol

The molar mass of scheelite can be calculated by summing the atomic masses of its constituent elements:

Molar mass of scheelite = Atomic mass of Ca + Atomic mass of W + 4 x Atomic mass of O = 40.08 g/mol + 183.84 g/mol + 4 x 16.00 g/mol = 40.08 g/mol + 183.84 g/mol + 64.00 g/mol = 288.92 g/mol

Now, we can calculate the mass of scheelite that contains 2.5 x 10^8 formula units:

Mass of scheelite = Number of formula units x Molar mass of scheelite = 2.5 x 10^8 x 288.92 g/mol = 7.23 x 10^10 g

Rounding the Answer to 2 Significant Digits

To round the answer to 2 significant digits, we need to look at the first two significant digits and the third digit. If the third digit is less than 5, we round down, and if it is 5 or greater, we round up.

In this case, the first two significant digits are 7.2, and the third digit is 3. Since 3 is less than 5, we round down to 7.2 x 10^10 g.

Conclusion

In conclusion, the mass of scheelite that contains a billion oxygen atoms is approximately 7.2 x 10^10 g. This calculation demonstrates the importance of understanding the composition and properties of scheelite and its constituent elements. By following the steps outlined in this article, you can calculate the mass of scheelite and other minerals with ease.

References

CRC Handbook of Chemistry and Physics, 97th Edition
IUPAC Periodic Table of Elements
Wikipedia: Scheelite

Q: What is the chemical formula of scheelite?

A: The chemical formula of scheelite is CaWO4, which indicates that it contains one calcium atom, one tungsten atom, and four oxygen atoms per formula unit.

Q: How many oxygen atoms are present in one formula unit of scheelite?

A: There are four oxygen atoms present in one formula unit of scheelite.

Q: How many formula units are present in a billion oxygen atoms?

A: To calculate the number of formula units, we divide the total number of oxygen atoms by the number of oxygen atoms per formula unit:

Number of formula units = Total number of oxygen atoms / Number of oxygen atoms per formula unit = 1.0 x 10^9 / 4 = 2.5 x 10^8 formula units

Q: What is the molar mass of scheelite?

A: The molar mass of scheelite can be calculated by summing the atomic masses of its constituent elements:

Molar mass of scheelite = Atomic mass of Ca + Atomic mass of W + 4 x Atomic mass of O = 40.08 g/mol + 183.84 g/mol + 4 x 16.00 g/mol = 40.08 g/mol + 183.84 g/mol + 64.00 g/mol = 288.92 g/mol

Q: How do I calculate the mass of scheelite that contains a billion oxygen atoms?

A: To calculate the mass of scheelite, we multiply the number of formula units by the molar mass of scheelite:

Mass of scheelite = Number of formula units x Molar mass of scheelite = 2.5 x 10^8 x 288.92 g/mol = 7.23 x 10^10 g

Q: How do I round the answer to 2 significant digits?

A: To round the answer to 2 significant digits, we look at the first two significant digits and the third digit. If the third digit is less than 5, we round down, and if it is 5 or greater, we round up.

In this case, the first two significant digits are 7.2, and the third digit is 3. Since 3 is less than 5, we round down to 7.2 x 10^10 g.

Q: What is the importance of oxygen atoms in scheelite?

A: Oxygen atoms play a crucial role in the structure and properties of scheelite. They form a tetrahedral arrangement around the tungsten atom, which is essential for the mineral's stability and its ability to exhibit unique optical and electrical properties.

Q: Can I use this method to calculate the mass of other minerals?

A: Yes, you can use this method to calculate the mass of other minerals by following the same steps:

Determine the chemical formula of the mineral.
Calculate the number of formula units present in the given amount of atoms.
Calculate the molar mass of the mineral.
Multiply the number of formula units by the molar mass to get the mass of the mineral.

Q: What are some common applications of scheelite?

A: Scheelite is a significant source of tungsten, which is highly valued for its high melting point, high density, and ability to withstand extremely high temperatures. Some common applications of scheelite include:

Steel production
Cement production
Aerospace industry
Electronics industry

Q: Where can I find more information on scheelite and its properties?

A: You can find more information on scheelite and its properties in various online resources, including:

Wikipedia: Scheelite
IUPAC Periodic Table of Elements
CRC Handbook of Chemistry and Physics, 97th Edition
Scientific journals and articles on mineralogy and chemistry.