Calculating Moles of Carbon Atoms

Oct 13, 2025 by miodeya.com 13 views

Understanding Mass-to-Mole Calculations

Mass-to-mole calculations are a crucial aspect of chemistry, allowing us to convert between the mass of a substance and the number of moles present. This type of calculation is essential in various chemical reactions, where the amount of reactants and products must be accurately determined. In this activity, we will focus on calculating the number of moles of carbon atoms in a given sample of carbon disulfide (CS2) using dimensional analysis.

The Mole Concept

Before diving into the calculation, it's essential to understand the mole concept. The mole (mol) is a unit of measurement that represents 6.022 x 10^23 particles, known as Avogadro's number. This concept allows us to relate the number of particles in a sample to its mass, making it a fundamental tool in chemistry.

Calculating Moles of Carbon Atoms

To calculate the number of moles of carbon atoms in 50.0 g of CS2, we need to follow a step-by-step approach using dimensional analysis.

Step 1: Write the given information

Mass of CS2: 50.0 g
Molar mass of CS2: 76.14 g/mol (calculated from the atomic masses of carbon and sulfur)
Atomic mass of carbon: 12.01 g/mol

Step 2: Determine the number of moles of CS2

To find the number of moles of CS2, we divide the given mass by the molar mass of CS2.

moles_CS2 = mass_CS2 / molar_mass_CS2

Step 3: Calculate the number of moles of carbon atoms

Since each molecule of CS2 contains one carbon atom, the number of moles of carbon atoms is equal to the number of moles of CS2.

moles_C = moles_CS2

Step 4: Perform the calculation

Now, let's perform the calculation using the given values.

mass_CS2 = 50.0 g
molar_mass_CS2 = 76.14 g/mol
moles_CS2 = mass_CS2 / molar_mass_CS2
moles_C = moles_CS2

Step 5: Calculate the result

Using the values above, we can calculate the result.

moles_C = 0.656 mol

Conclusion

In this activity, we calculated the number of moles of carbon atoms in 50.0 g of CS2 using dimensional analysis. By following the step-by-step approach outlined above, we were able to determine the number of moles of carbon atoms present in the given sample. This type of calculation is essential in various chemical reactions, where the amount of reactants and products must be accurately determined.

Key Takeaways

Mass-to-mole calculations are a crucial aspect of chemistry.
The mole concept allows us to relate the number of particles in a sample to its mass.
Dimensional analysis is a powerful tool for performing mass-to-mole calculations.
The number of moles of carbon atoms is equal to the number of moles of CS2.

Practice Problems

Calculate the number of moles of oxygen atoms in 25.0 g of O2.
Determine the number of moles of nitrogen atoms in 30.0 g of N2.
Calculate the number of moles of hydrogen atoms in 20.0 g of H2.

Solutions

moles_O2 = 0.328 mol
moles_N2 = 0.394 mol
moles_H2 = 1.067 mol

Additional Resources

Molar mass of CS2: 76.14 g/mol
Atomic mass of carbon: 12.01 g/mol
Atomic mass of sulfur: 32.07 g/mol

Frequently Asked Questions

In this Q&A article, we will address some of the most common questions related to mass-to-mole calculations, including dimensional analysis and the mole concept.

Q: What is the mole concept?

A: The mole concept is a fundamental principle in chemistry that relates the number of particles in a sample to its mass. One mole of a substance contains 6.022 x 10^23 particles, known as Avogadro's number.

Q: How do I perform a mass-to-mole calculation using dimensional analysis?

A: To perform a mass-to-mole calculation using dimensional analysis, follow these steps:

Write the given information, including the mass of the substance and its molar mass.
Determine the number of moles of the substance by dividing the given mass by the molar mass.
Calculate the number of moles of the substance.
Perform the calculation using the given values.

Q: What is the difference between a mole and a gram?

A: A mole is a unit of measurement that represents 6.022 x 10^23 particles, while a gram is a unit of mass. One mole of a substance has a mass equal to its molar mass.

Q: How do I calculate the number of moles of a substance from its mass?

A: To calculate the number of moles of a substance from its mass, divide the given mass by the molar mass of the substance.

Q: What is the significance of Avogadro's number?

A: Avogadro's number (6.022 x 10^23) is a fundamental constant in chemistry that relates the number of particles in a sample to its mass. It is used to calculate the number of moles of a substance from its mass.

Q: Can I use dimensional analysis to calculate the number of moles of a substance from its mass?

A: Yes, dimensional analysis is a powerful tool for performing mass-to-mole calculations. By following the step-by-step approach outlined above, you can calculate the number of moles of a substance from its mass.

Q: What are some common mistakes to avoid when performing mass-to-mole calculations?

A: Some common mistakes to avoid when performing mass-to-mole calculations include:

Not using the correct molar mass of the substance
Not performing the calculation correctly
Not checking the units of the answer

Q: How can I practice mass-to-mole calculations?

A: You can practice mass-to-mole calculations by working through practice problems, such as those listed below.

Practice Problems

Calculate the number of moles of oxygen atoms in 25.0 g of O2.
Determine the number of moles of nitrogen atoms in 30.0 g of N2.
Calculate the number of moles of hydrogen atoms in 20.0 g of H2.

Solutions

moles_O2 = 0.328 mol
moles_N2 = 0.394 mol
moles_H2 = 1.067 mol

Additional Resources

Molar mass of CS2: 76.14 g/mol
Atomic mass of carbon: 12.01 g/mol
Atomic mass of sulfur: 32.07 g/mol

By following the step-by-step approach outlined in this Q&A article, you should be able to address some of the most common questions related to mass-to-mole calculations, including dimensional analysis and the mole concept. Remember to practice these calculations to become proficient in mass-to-mole conversions.