Understanding the Molar Mass

Oct 13, 2025 by wbrum.org 124 views

Introduction

In chemistry, determining the molecular formula of a compound is crucial for understanding its structure and properties. The molecular formula is a representation of the number and types of atoms present in a molecule. Given the molar mass of a compound, we can calculate its molecular formula using the atomic masses of its constituent elements. In this article, we will explore how to determine the molecular formula of the compound CH2 with a molar mass of 168 g/mol.

Understanding the Molar Mass

The molar mass of a compound is the sum of the atomic masses of its constituent atoms. The atomic mass of an element is the average mass of its naturally occurring isotopes. The molar mass of the compound CH2 is given as 168 g/mol. To determine the molecular formula, we need to calculate the number of moles of each element present in the compound.

Calculating the Number of Moles of Each Element

The atomic mass of carbon (C) is 12.01 g/mol, and the atomic mass of hydrogen (H) is 1.008 g/mol. We can calculate the number of moles of each element present in the compound using the following formula:

Number of moles = (Mass of element / Atomic mass of element)

For carbon:

Number of moles of C = (Mass of C / Atomic mass of C) = (12.01 g/mol / 12.01 g/mol) = 1 mole

For hydrogen:

Number of moles of H = (Mass of H / Atomic mass of H) = (2 x 1.008 g/mol / 1.008 g/mol) = 2 moles

Determining the Molecular Formula

Now that we have calculated the number of moles of each element present in the compound, we can determine the molecular formula. The molecular formula is a representation of the number and types of atoms present in a molecule. In this case, we have 1 mole of carbon and 2 moles of hydrogen.

To determine the molecular formula, we need to multiply the number of moles of each element by the atomic mass of each element and then add the results. This will give us the total mass of each element present in the compound.

For carbon:

Mass of C = Number of moles of C x Atomic mass of C = 1 mole x 12.01 g/mol = 12.01 g/mol

For hydrogen:

Mass of H = Number of moles of H x Atomic mass of H = 2 moles x 1.008 g/mol = 2.016 g/mol

Calculating the Molecular Formula

Now that we have calculated the mass of each element present in the compound, we can determine the molecular formula. The molecular formula is a representation of the number and types of atoms present in a molecule.

To determine the molecular formula, we need to divide the mass of each element by its atomic mass and then multiply the result by the atomic mass of the element. This will give us the number of atoms of each element present in the molecule.

For carbon:

Number of atoms of C = (Mass of C / Atomic mass of C) = (12.01 g/mol / 12.01 g/mol) = 1

For hydrogen:

Number of atoms of H = (Mass of H / Atomic mass of H) = (2.016 g/mol / 1.008 g/mol) = 2

Conclusion

In conclusion, the molecular formula of the compound CH2 with a molar mass of 168 g/mol is C8H16. This is because we have 1 mole of carbon and 2 moles of hydrogen, which corresponds to 8 carbon atoms and 16 hydrogen atoms.

Final Answer

The final answer is C8H16.

Discussion

The molecular formula of a compound is a crucial piece of information that can be used to understand its structure and properties. In this article, we have explored how to determine the molecular formula of the compound CH2 with a molar mass of 168 g/mol. We have calculated the number of moles of each element present in the compound and then determined the molecular formula using the atomic masses of the constituent elements.

References

Atomic masses of elements: [1]
Molar mass of compound: [2]

Footnotes

[1] Atomic masses of elements: The atomic masses of elements are the average masses of their naturally occurring isotopes. The atomic mass of carbon is 12.01 g/mol, and the atomic mass of hydrogen is 1.008 g/mol.

[2] Molar mass of compound: The molar mass of the compound CH2 is given as 168 g/mol.

Introduction
Understanding the Molar Mass
Calculating the Number of Moles of Each Element
Determining the Molecular Formula
Calculating the Molecular Formula
Conclusion
Final Answer
Discussion
References
Footnotes
Table of Contents