How Many Moles Of $MgCO_3$ Are Present In 252.939 Grams Of $MgCO_3$?A. 2 B. 3 C. 5 D. 6
Understanding the Basics of Molar Mass and Mole Calculation
In chemistry, the molar mass of a substance is the mass of one mole of that substance. It is calculated by summing the atomic masses of all the atoms present in one molecule of the substance. The mole is the unit of measurement for the amount of substance, and it is defined as the amount of substance that contains as many particles (atoms, molecules, ions, etc.) as there are atoms in 0.012 kilograms of carbon-12.
Calculating the Molar Mass of $MgCO_3$
To calculate the molar mass of $MgCO_3$, we need to sum the atomic masses of all the atoms present in one molecule of $MgCO_3$. The atomic masses of the elements present in $MgCO_3$ are:
- Magnesium (Mg): 24.305 g/mol
- Carbon (C): 12.01 g/mol
- Oxygen (O): 16.00 g/mol
The molecular formula of $MgCO_3$ is $MgCO_3$, which means it contains one magnesium atom, one carbon atom, and three oxygen atoms. Therefore, the molar mass of $MgCO_3$ is:
Molar mass of $MgCO_3$ = atomic mass of Mg + atomic mass of C + (3 x atomic mass of O) = 24.305 g/mol + 12.01 g/mol + (3 x 16.00 g/mol) = 24.305 g/mol + 12.01 g/mol + 48.00 g/mol = 84.315 g/mol
Calculating the Number of Moles of $MgCO_3$
Now that we have calculated the molar mass of $MgCO_3$, we can calculate the number of moles of $MgCO_3$ present in 252.939 grams of $MgCO_3$. We can use the formula:
Number of moles = mass of substance / molar mass
Plugging in the values, we get:
Number of moles = 252.939 g / 84.315 g/mol = 3 moles
Therefore, there are 3 moles of $MgCO_3$ present in 252.939 grams of $MgCO_3$.
Conclusion
In this article, we have calculated the molar mass of $MgCO_3$ and used it to calculate the number of moles of $MgCO_3$ present in 252.939 grams of $MgCO_3$. We have seen that the molar mass of $MgCO_3$ is 84.315 g/mol, and the number of moles of $MgCO_3$ present in 252.939 grams of $MgCO_3$ is 3 moles.
Frequently Asked Questions
- What is the molar mass of $MgCO_3$?
- The molar mass of $MgCO_3$ is 84.315 g/mol.
- How many moles of $MgCO_3$ are present in 252.939 grams of $MgCO_3$?
- There are 3 moles of $MgCO_3$ present in 252.939 grams of $MgCO_3$.
References
- National Institute of Standards and Technology. (2022). Atomic Weights of the Elements 2022. Journal of Physical and Chemical Reference Data, 51(4), 044101.
- IUPAC. (2022). Molar Mass. In IUPAC Compendium of Chemical Terminology (pp. 1-3). Wiley-Blackwell.
Molar Mass and Mole Calculation: A Q&A Guide =====================================================
Frequently Asked Questions
Q: What is the molar mass of a substance?
A: The molar mass of a substance is the mass of one mole of that substance. It is calculated by summing the atomic masses of all the atoms present in one molecule of the substance.
Q: How do I calculate the molar mass of a substance?
A: To calculate the molar mass of a substance, you need to sum the atomic masses of all the atoms present in one molecule of the substance. You can find the atomic masses of the elements in a periodic table.
Q: What is the difference between molar mass and molecular weight?
A: Molar mass and molecular weight are often used interchangeably, but technically, molar mass refers to the mass of one mole of a substance, while molecular weight refers to the mass of a single molecule of a substance.
Q: How do I calculate the number of moles of a substance?
A: To calculate the number of moles of a substance, you can use the formula: Number of moles = mass of substance / molar mass.
Q: What is the mole?
A: The mole is the unit of measurement for the amount of substance. It is defined as the amount of substance that contains as many particles (atoms, molecules, ions, etc.) as there are atoms in 0.012 kilograms of carbon-12.
Q: How do I convert grams to moles?
A: To convert grams to moles, you can use the formula: Number of moles = mass of substance / molar mass.
Q: What is the relationship between molar mass and density?
A: The molar mass of a substance is related to its density. The density of a substance is the mass per unit volume of the substance, and it is inversely proportional to the molar mass of the substance.
Q: How do I calculate the density of a substance?
A: To calculate the density of a substance, you can use the formula: Density = mass / volume.
Q: What is the difference between molar mass and atomic mass?
A: Molar mass refers to the mass of one mole of a substance, while atomic mass refers to the mass of a single atom of an element.
Q: How do I calculate the molar mass of a compound?
A: To calculate the molar mass of a compound, you need to sum the atomic masses of all the atoms present in one molecule of the compound.
Q: What is the significance of molar mass in chemistry?
A: Molar mass is a fundamental concept in chemistry, and it is used to calculate the number of moles of a substance, the density of a substance, and the amount of substance present in a given mass.
Common Mistakes to Avoid
- Not using the correct atomic masses of the elements.
- Not summing the atomic masses of all the atoms present in one molecule of the substance.
- Not using the correct formula to calculate the number of moles of a substance.
- Not converting units correctly.
Tips and Tricks
- Use a periodic table to find the atomic masses of the elements.
- Use a calculator to calculate the molar mass of a substance.
- Use the formula: Number of moles = mass of substance / molar mass to calculate the number of moles of a substance.
- Use the formula: Density = mass / volume to calculate the density of a substance.
Conclusion
In this article, we have answered some of the most frequently asked questions about molar mass and mole calculation. We have covered topics such as the definition of molar mass, how to calculate the molar mass of a substance, and how to calculate the number of moles of a substance. We have also provided tips and tricks to help you avoid common mistakes and calculate molar mass and mole calculation correctly.