Explanations 
Textbooks 
Exams 
GCSE 
IGCSE 
AS 
A Level 
International A Level 
University Admissions Tests 
Flashcards 
Vaia AI 
Notes 
Study Plans 
Study Sets 
Find a job 
Find a degree 
Student Deals 
Magazine 
Mobile App Chapter 9: Problem 132
Determine the mass percent of each element in magnesium phosphate.
Short Answer
Expert verified
The mass percent of each element in magnesium phosphate (Mg3(PO4)2) is as follows: Magnesium (Mg): 27.75%, Phosphorus (P): 23.58%, and Oxygen (O): 48.67%.
Step by step solution
01
Find the molecular formula of magnesium phosphate
The molecular formula for magnesium phosphate is Mg3(PO4)2. We have three magnesium atoms, two phosphate ions (which consist of one phosphorus and four oxygen atoms each), so that's 3Mg + 2(1P + 4O).
02
Find the molar mass of magnesium, phosphorus, and oxygen
Using the periodic table, we can find the molar mass values of each element:
- Magnesium (Mg): 24.305 g/mol
- Phosphorus (P): 30.974 g/mol
- Oxygen (O): 16.00 g/mol
03
Calculate the molar mass of magnesium phosphate
The molar mass of magnesium phosphate (Mg3(PO4)2) is the sum of the molar masses of all the atoms in the compound.
Molar mass of Mg3(PO4)2 = 3(24.305 g/mol) + (2)(1(30.974 g/mol) + 4(16.00 g/mol))
= 3(24.305) + 2(30.974 + 4(16.00))
= 72.915 + 2(30.974 + 64)
= 72.915 + 2(94.974)
= 72.915 + 189.948
= 262.863 g/mol
The molar mass of magnesium phosphate is 262.863 g/mol.
04
Calculate the mass percent of each element
Now we will calculate the mass percent of each element in magnesium phosphate using the formula:
Mass percent = (Mass of element in the compound / Molar mass of the compound) x 100
Mass percent of Magnesium (Mg):
= (3(24.305) / 262.863) x 100
= (72.915 / 262.863) x 100
= 27.75 %
Mass percent of Phosphorus (P):
= (2(30.974) / 262.863) x 100
= (61.948 / 262.863) x 100
= 23.58 %
Mass percent of Oxygen (O):
= (8(16) / 262.863) x 100
= (128 / 262.863) x 100
= 48.67 %
The mass percent of each element in magnesium phosphate is as follows:
- Magnesium (Mg): 27.75%
- Phosphorus (P): 23.58%
- Oxygen (O): 48.67%
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with Vaia!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Molar Mass
Understanding molar mass is essential for solving problems related to mass percent composition. In simple terms, molar mass is the weight of one mole of a substance, usually expressed in grams per mole (g/mol). It corresponds to the sum of the atomic masses of all the atoms in a molecular formula.
For instance, let's consider the compound magnesium phosphate, with the molecular formula Mg3(PO4)2. Each element contributes to the total molar mass of the compound, proportionally to the number of atoms present. Calculating the molar mass involves multiplying the atomic mass of each element by the number of times that element appears in the formula and then summing these values together. The accurate determination of molar mass is a crucial step when computing the mass percent composition of each element in a compound.
For instance, let's consider the compound magnesium phosphate, with the molecular formula Mg3(PO4)2. Each element contributes to the total molar mass of the compound, proportionally to the number of atoms present. Calculating the molar mass involves multiplying the atomic mass of each element by the number of times that element appears in the formula and then summing these values together. The accurate determination of molar mass is a crucial step when computing the mass percent composition of each element in a compound.
Molecular Formula
The molecular formula provides critical information regarding the specific number and type of atoms that compose a molecule. For our exercise involving magnesium phosphate (Mg3(PO4)2), the molecular formula indicates the molecule consists of three magnesium atoms, two phosphorus atoms, and eight oxygen atoms.
The molecular formula is not only an indicator of the compound's composition but also serves as a blueprint for quantifying elements when determining their mass percent in the compound. Understanding the molecular formula is necessary for accurately calculating both the molar mass and the mass percent composition.
The molecular formula is not only an indicator of the compound's composition but also serves as a blueprint for quantifying elements when determining their mass percent in the compound. Understanding the molecular formula is necessary for accurately calculating both the molar mass and the mass percent composition.
Elemental Composition
When examining the elemental composition of a compound, we are essentially looking at the types of elements present and their relative quantities. In stoichiometric calculations, it's essential to know the exact count of each type of atom in the compound.
For example, in magnesium phosphate, the elemental composition consists of magnesium (Mg), phosphorus (P), and oxygen (O). By using the molecular formula, we can determine that there are three magnesium atoms, two phosphorus atoms, and eight oxygen atoms, giving us the ratios required to calculate the mass percent composition of each element within the compound.
For example, in magnesium phosphate, the elemental composition consists of magnesium (Mg), phosphorus (P), and oxygen (O). By using the molecular formula, we can determine that there are three magnesium atoms, two phosphorus atoms, and eight oxygen atoms, giving us the ratios required to calculate the mass percent composition of each element within the compound.
Stoichiometry
The core of chemistry calculations lies within stoichiometry, the area of chemistry that pertains to the quantitative relationships between reactants and products in a chemical reaction. However, it is also crucial when it comes to finding mass percent compositions.
Stoichiometry allows us to convert between grams and moles, using molar mass as a conversion factor. This provides a bridge between the atomic scale (where the molecular formula is useful) and the macroscopic scale (where grams are measured). By applying stoichiometric principles, we can determine the mass percent composition, illustrating the distribution of mass among the different elements in a compound.
Stoichiometry allows us to convert between grams and moles, using molar mass as a conversion factor. This provides a bridge between the atomic scale (where the molecular formula is useful) and the macroscopic scale (where grams are measured). By applying stoichiometric principles, we can determine the mass percent composition, illustrating the distribution of mass among the different elements in a compound.
