a 5.15g sample of a hydrocarbon is burned in oxygen, producing 15.6g of carbon dioxide and 8.45g of water. Assuming an excess of oxygen, what is the empirical formula of the hydrocarbon?
i just need to add that i need to know how to set up the problem not just the answer
Well, you've posed quite a chemical question there! But don't worry, I'm here to help with a touch of humor. Let's dive in!
To find the empirical formula of the hydrocarbon, we first need to determine the number of moles of carbon and hydrogen in the compound.
Given that 5.15g of the hydrocarbon produces 15.6g of carbon dioxide, we can calculate the number of moles of carbon by dividing the mass of carbon dioxide by its molar mass.
Now, carbon dioxide (CO2) has a molar mass of approximately 44g/mol. So, 15.6g of carbon dioxide is equal to 15.6g/mol / 44g/mol, which is roughly 0.35 moles of carbon.
Next, let's calculate the number of moles of hydrogen. We know that 5.15g of the hydrocarbon produces 8.45g of water (H2O). Water has a molar mass of approximately 18g/mol. So, 8.45g of water is equal to 8.45g/mol / 18g/mol, which is approximately 0.47 moles of hydrogen.
Now, to find the empirical formula, we need to find the ratio of carbon to hydrogen. The simplest whole number ratio between 0.35 and 0.47 is 3:4. This means that the empirical formula of the hydrocarbon is C3H4.
So, there you have it! The empirical formula of the hydrocarbon is C3H4. Hope that helps, and always remember to keep the chemistry jokes in the lab!
To find the empirical formula of the hydrocarbon, we need to determine the ratio of carbon and hydrogen atoms present in the compound.
1. Start by calculating the number of moles of carbon dioxide produced.
- The molar mass of carbon dioxide (CO2) is 44.01 g/mol.
- Number of moles of CO2 = mass of CO2 / molar mass of CO2 = 15.6 g / 44.01 g/mol.
2. Next, calculate the number of moles of water produced.
- The molar mass of water (H2O) is 18.02 g/mol.
- Number of moles of H2O = mass of H2O / molar mass of H2O = 8.45 g / 18.02 g/mol.
3. Determine the number of moles of carbon and hydrogen present in the hydrocarbon.
- Each mole of CO2 contains 1 mole of carbon.
- Each mole of H2O contains 2 moles of hydrogen.
Therefore, the number of moles of carbon in the hydrocarbon = number of moles of CO2.
And, the number of moles of hydrogen in the hydrocarbon = 2 * number of moles of H2O.
4. Calculate the ratio of moles of carbon to hydrogen.
Divide the number of moles of carbon by the number of moles of hydrogen to determine the simplest whole-number ratio.
5. Use the ratio from step 4 to derive the empirical formula.
Write the empirical formula using the whole-number ratio obtained.
Note: Make sure to round the ratio of moles of carbon to hydrogen to the nearest whole number.
So, let's calculate:
1. Number of moles of CO2 = 15.6 g / 44.01 g/mol ≈ 0.354 mol
2. Number of moles of H2O = 8.45 g / 18.02 g/mol ≈ 0.468 mol
3. Number of moles of carbon = 0.354 mol (from CO2)
Number of moles of hydrogen = 2 * 0.468 mol (from H2O) ≈ 0.936 mol
4. Ratio of moles of carbon to hydrogen ≈ 0.354 mol / 0.936 mol ≈ 0.378.
Rounding the ratio to the nearest whole number, we get a ratio of 1:3.
Therefore, the empirical formula of the hydrocarbon is CH3.
(Note: The assumption of excess oxygen indicates that all the carbon in the hydrocarbon is converted to carbon dioxide, and all the hydrogen is converted to water.)
To determine the empirical formula of a hydrocarbon, we need to calculate the ratio of the elements present in the compound. In this case, we have the masses of carbon dioxide and water produced from the combustion of the hydrocarbon.
1. Calculate the moles of carbon dioxide:
- The molar mass of carbon dioxide (CO2) is 44 g/mol.
- Divide the mass of carbon dioxide (15.6 g) by its molar mass (44 g/mol) to get the moles of carbon dioxide.
Moles of CO2 = 15.6 g / 44 g/mol
2. Calculate the moles of water:
- The molar mass of water (H2O) is 18 g/mol.
- Divide the mass of water (8.45 g) by its molar mass (18 g/mol) to get the moles of water.
Moles of H2O = 8.45 g / 18 g/mol
3. Calculate the moles of carbon in the hydrocarbon:
- One mole of carbon dioxide (CO2) contains one mole of carbon.
- Multiply the moles of carbon dioxide by the ratio of carbon to carbon dioxide.
Moles of carbon = Moles of CO2
4. Calculate the moles of hydrogen in the hydrocarbon:
- One mole of water (H2O) contains two moles of hydrogen.
- Multiply the moles of water by the ratio of hydrogen to water.
Moles of hydrogen = 2 * Moles of H2O
5. Divide the moles of each element by the smallest number of moles obtained in steps 3 and 4.
- This will give us the simplest ratio between carbon and hydrogen atoms.
Simplest ratio = Moles of carbon / Smallest number of moles obtained
Now, we have the simplest ratio of carbon to hydrogen atoms in the hydrocarbon, which will give us the empirical formula.
For example, if the simplest ratio is 2:5, the empirical formula would be C2H5.
Calculate the moles of carbon dioxide:
Moles of CO2 = 15.6 g / 44 g/mol = 0.3545 mol
Calculate the moles of water:
Moles of H2O = 8.45 g / 18 g/mol = 0.4694 mol
Since the moles of carbon dioxide and water are approximately equal (within experimental error), we can assume that the ratio of carbon to hydrogen is 1:1.
Therefore, the empirical formula of the hydrocarbon is CH.