The Mass of a Single Molecule of Aspirin

Oct 13, 2025 by wbrum.org 97 views

Introduction

Aspirin, also known as acetylsalicylic acid, is a widely used medication for pain relief and anti-inflammatory purposes. It is a compound with the chemical formula C_9H_8O_4. In this article, we will calculate the mass of 1.20 x 10^21 molecules of aspirin.

The Molar Mass of Aspirin

To calculate the mass of a molecule, we need to know its molar mass. The molar mass of a compound is the sum of the atomic masses of its constituent atoms. The atomic masses of carbon (C), hydrogen (H), and oxygen (O) are 12.01 g/mol, 1.008 g/mol, and 16.00 g/mol, respectively.

The molar mass of aspirin (C_9H_8O_4) can be calculated as follows:

Molar mass of C_9H_8O_4 = (9 x 12.01 g/mol) + (8 x 1.008 g/mol) + (4 x 16.00 g/mol) = 108.09 g/mol + 8.064 g/mol + 64.00 g/mol = 180.154 g/mol

The Mass of a Single Molecule of Aspirin

The mass of a single molecule of aspirin can be calculated by dividing the molar mass by Avogadro's number (6.022 x 10^23 molecules/mol).

Mass of a single molecule of aspirin = Molar mass of C_9H_8O_4 / Avogadro's number = 180.154 g/mol / (6.022 x 10^23 molecules/mol) = 2.99 x 10^-22 g

The Mass of 1.20 x 10^21 Molecules of Aspirin

To calculate the mass of 1.20 x 10^21 molecules of aspirin, we can multiply the mass of a single molecule by the number of molecules.

Mass of 1.20 x 10^21 molecules of aspirin = Mass of a single molecule of aspirin x Number of molecules = (2.99 x 10^-22 g) x (1.20 x 10^21) = 3.57 x 10^-1 g

Conclusion

The mass of 1.20 x 10^21 molecules of aspirin is 3.57 x 10^-1 g or 0.357 g.

References

CRC Handbook of Chemistry and Physics, 97th Edition
IUPAC, Compendium of Chemical Terminology, 2nd Edition

Introduction

In our previous article, we calculated the mass of 1.20 x 10^21 molecules of aspirin, C_9H_8O_4. In this article, we will answer some frequently asked questions related to this topic.

Q: What is the molar mass of aspirin?

A: The molar mass of aspirin (C_9H_8O_4) is 180.154 g/mol.

Q: How do you calculate the mass of a single molecule of aspirin?

A: To calculate the mass of a single molecule of aspirin, you need to divide the molar mass by Avogadro's number (6.022 x 10^23 molecules/mol).

Q: What is Avogadro's number?

A: Avogadro's number is a constant that represents the number of molecules in one mole of a substance. It is equal to 6.022 x 10^23 molecules/mol.

Q: How do you calculate the mass of 1.20 x 10^21 molecules of aspirin?

A: To calculate the mass of 1.20 x 10^21 molecules of aspirin, you need to multiply the mass of a single molecule by the number of molecules.

Q: What is the mass of 1.20 x 10^21 molecules of aspirin?

A: The mass of 1.20 x 10^21 molecules of aspirin is 3.57 x 10^-1 g or 0.357 g.

Q: How do you express the answer in three significant figures?

A: To express the answer in three significant figures, you need to round the answer to three significant figures. In this case, the answer is 0.357 g.

Q: What is the significance of the mass of 1.20 x 10^21 molecules of aspirin?

A: The mass of 1.20 x 10^21 molecules of aspirin is significant because it represents a large number of molecules, and it can be used to calculate the mass of a substance in a laboratory setting.

Q: How do you calculate the mass of a substance in a laboratory setting?

A: To calculate the mass of a substance in a laboratory setting, you need to use a balance or a mass spectrometer to measure the mass of the substance.

Q: What is the difference between a balance and a mass spectrometer?

A: A balance is a device that measures the mass of a substance by comparing it to a known mass, while a mass spectrometer is a device that measures the mass of a substance by ionizing it and measuring the mass-to-charge ratio.

Q: How do you use a balance to measure the mass of a substance?

A: To use a balance to measure the mass of a substance, you need to place the substance on the balance and compare it to a known mass. The balance will display the mass of the substance.

Q: How do you use a mass spectrometer to measure the mass of a substance?

A: To use a mass spectrometer to measure the mass of a substance, you need to ionize the substance and measure the mass-to-charge ratio. The mass spectrometer will display the mass of the substance.

Conclusion

In this article, we have answered some frequently asked questions related to the mass of 1.20 x 10^21 molecules of aspirin, C_9H_8O_4. We hope that this article has been helpful in understanding the concept of mass and how to calculate it in a laboratory setting.

References

CRC Handbook of Chemistry and Physics, 97th Edition
IUPAC, Compendium of Chemical Terminology, 2nd Edition
National Institute of Standards and Technology, Mass Spectrometry