Calculate the molar mass of Mg3(PO4)2
The Correct Answer and Explanation is :
The correct answer is: 262.87 g/mol.
To calculate the molar mass of magnesium phosphate, Mg₃(PO₄)₂, we need to determine the molar masses of each constituent element and sum them according to the formula.
Step-by-Step Calculation
- Identify the elements and their quantities in the formula:
- Magnesium (Mg): There are 3 magnesium atoms.
- Phosphorus (P): There are 2 phosphorus atoms.
- Oxygen (O): There are 8 oxygen atoms (since there are 4 oxygen atoms in each phosphate group, and there are 2 phosphate groups).
- Find the molar masses of the elements:
- Magnesium (Mg): Approximately 24.31 g/mol
- Phosphorus (P): Approximately 30.97 g/mol
- Oxygen (O): Approximately 16.00 g/mol
- Calculate the contribution of each element:
- For magnesium:
[
3 \, \text{Mg} \times 24.31 \, \text{g/mol} = 72.93 \, \text{g/mol}
] - For phosphorus:
[
2 \, \text{P} \times 30.97 \, \text{g/mol} = 61.94 \, \text{g/mol}
] - For oxygen:
[
8 \, \text{O} \times 16.00 \, \text{g/mol} = 128.00 \, \text{g/mol}
]
- Sum the contributions:
[
\text{Molar mass of Mg}_3(\text{PO}_4)_2 = 72.93 \, \text{g/mol} + 61.94 \, \text{g/mol} + 128.00 \, \text{g/mol}
]
[
= 262.87 \, \text{g/mol}
]
Conclusion
The molar mass of magnesium phosphate, Mg₃(PO₄)₂, is approximately 262.87 g/mol.
Explanation
The molar mass is a fundamental property in chemistry, representing the mass of one mole of a substance in grams. It is crucial for stoichiometric calculations, allowing chemists to convert between moles and grams effectively. The calculation involves multiplying the atomic mass of each element by the number of times it appears in the compound and summing these values. This process not only applies to simple ionic compounds like magnesium phosphate but also to more complex molecules, facilitating various applications, such as determining the amounts of reactants needed for reactions and the yields of products formed. Understanding molar mass is essential for anyone studying chemistry, as it forms the basis for quantifying chemical substances in laboratory settings and industrial applications.