Determine The Empirical Formula For Each Compound.A Compound Contains:- 0.390 Mol Carbon- 2.34 Mol Hydrogen- 0.130 Mol OxygenCalculate The Mass Of Each Element:- Carbon: $0.390 \, \text{mol} \times \frac{12.01 \, \text{g}}{1 \, \text{mol}} = 4.683
Introduction
In chemistry, determining the empirical formula of a compound is a crucial step in understanding its composition and structure. The empirical formula represents the simplest whole-number ratio of atoms of each element present in the compound. In this article, we will walk you through the process of determining the empirical formula for a given compound.
Calculating the Mass of Each Element
To determine the empirical formula, we first need to calculate the mass of each element present in the compound. We are given the following information:
- 0.390 mol carbon
- 2.34 mol hydrogen
- 0.130 mol oxygen
We can calculate the mass of each element using the following formula:
mass = number of moles × molar mass
For carbon:
mass = 0.390 mol × 12.01 g/mol = 4.683 g
For hydrogen:
mass = 2.34 mol × 1.008 g/mol = 2.365 g
For oxygen:
mass = 0.130 mol × 16.00 g/mol = 2.080 g
Converting Mass to Moles
Next, we need to convert the mass of each element to moles. We can do this by dividing the mass by the molar mass of each element.
For carbon:
moles = mass ÷ molar mass = 4.683 g ÷ 12.01 g/mol = 0.390 mol
For hydrogen:
moles = mass ÷ molar mass = 2.365 g ÷ 1.008 g/mol = 2.34 mol
For oxygen:
moles = mass ÷ molar mass = 2.080 g ÷ 16.00 g/mol = 0.130 mol
Determining the Empirical Formula
Now that we have the number of moles of each element, we can determine the empirical formula by finding the simplest whole-number ratio of atoms of each element.
To do this, we need to divide each number of moles by the smallest number of moles (in this case, 0.130 mol).
For carbon:
ratio = 0.390 mol ÷ 0.130 mol = 3.00
For hydrogen:
ratio = 2.34 mol ÷ 0.130 mol = 18.00
For oxygen:
ratio = 0.130 mol ÷ 0.130 mol = 1.00
The empirical formula is therefore C3H18O.
Conclusion
In this article, we have walked you through the process of determining the empirical formula for a given compound. We calculated the mass of each element, converted the mass to moles, and then determined the empirical formula by finding the simplest whole-number ratio of atoms of each element. The empirical formula for the given compound is C3H18O.
Calculating the Mass of Each Element: A Step-by-Step Guide
Step 1: Calculate the Mass of Carbon
To calculate the mass of carbon, we multiply the number of moles by the molar mass.
mass = number of moles × molar mass = 0.390 mol × 12.01 g/mol = 4.683 g
Step 2: Calculate the Mass of Hydrogen
To calculate the mass of hydrogen, we multiply the number of moles by the molar mass.
mass = number of moles × molar mass = 2.34 mol × 1.008 g/mol = 2.365 g
Step 3: Calculate the Mass of Oxygen
To calculate the mass of oxygen, we multiply the number of moles by the molar mass.
mass = number of moles × molar mass = 0.130 mol × 16.00 g/mol = 2.080 g
Step 4: Convert Mass to Moles
To convert the mass of each element to moles, we divide the mass by the molar mass.
For carbon:
moles = mass ÷ molar mass = 4.683 g ÷ 12.01 g/mol = 0.390 mol
For hydrogen:
moles = mass ÷ molar mass = 2.365 g ÷ 1.008 g/mol = 2.34 mol
For oxygen:
moles = mass ÷ molar mass = 2.080 g ÷ 16.00 g/mol = 0.130 mol
Step 5: Determine the Empirical Formula
To determine the empirical formula, we need to find the simplest whole-number ratio of atoms of each element. We do this by dividing each number of moles by the smallest number of moles (in this case, 0.130 mol).
For carbon:
ratio = 0.390 mol ÷ 0.130 mol = 3.00
For hydrogen:
ratio = 2.34 mol ÷ 0.130 mol = 18.00
For oxygen:
ratio = 0.130 mol ÷ 0.130 mol = 1.00
The empirical formula is therefore C3H18O.
Frequently Asked Questions
Q: What is the empirical formula?
A: The empirical formula is the simplest whole-number ratio of atoms of each element present in a compound.
Q: How do I calculate the mass of each element?
A: To calculate the mass of each element, you multiply the number of moles by the molar mass.
Q: How do I convert mass to moles?
A: To convert mass to moles, you divide the mass by the molar mass.
Q: How do I determine the empirical formula?
Q&A: Determining Empirical Formulas
Q: What is the empirical formula?
A: The empirical formula is the simplest whole-number ratio of atoms of each element present in a compound. It represents the basic building blocks of a compound and is used to describe its composition.
Q: How do I calculate the mass of each element?
A: To calculate the mass of each element, you multiply the number of moles by the molar mass. For example, if you have 0.390 mol of carbon, the mass would be:
mass = number of moles × molar mass = 0.390 mol × 12.01 g/mol = 4.683 g
Q: How do I convert mass to moles?
A: To convert mass to moles, you divide the mass by the molar mass. For example, if you have 4.683 g of carbon, the number of moles would be:
moles = mass ÷ molar mass = 4.683 g ÷ 12.01 g/mol = 0.390 mol
Q: How do I determine the empirical formula?
A: To determine the empirical formula, you need to find the simplest whole-number ratio of atoms of each element. You do this by dividing each number of moles by the smallest number of moles. For example, if you have the following numbers of moles:
- Carbon: 0.390 mol
- Hydrogen: 2.34 mol
- Oxygen: 0.130 mol
You would divide each number of moles by the smallest number of moles (0.130 mol) to get the following ratios:
- Carbon: 0.390 mol ÷ 0.130 mol = 3.00
- Hydrogen: 2.34 mol ÷ 0.130 mol = 18.00
- Oxygen: 0.130 mol ÷ 0.130 mol = 1.00
The empirical formula is therefore C3H18O.
Q: What is the difference between the empirical formula and the molecular formula?
A: The empirical formula represents the simplest whole-number ratio of atoms of each element present in a compound, while the molecular formula represents the actual number of atoms of each element present in a molecule of the compound.
Q: How do I determine the molecular formula?
A: To determine the molecular formula, you need to know the molar mass of the compound and the number of moles of each element present. You can then use the following formula to calculate the molecular formula:
molecular formula = empirical formula × (molar mass ÷ (empirical formula mass × number of moles))
Q: What are some common mistakes to avoid when determining empirical formulas?
A: Some common mistakes to avoid when determining empirical formulas include:
- Not converting mass to moles correctly
- Not finding the simplest whole-number ratio of atoms of each element
- Not considering the molar mass of the compound when determining the molecular formula
Conclusion
Determining empirical formulas is an important step in understanding the composition of a compound. By following the steps outlined in this article, you can determine the empirical formula of a compound and gain a deeper understanding of its structure and properties.