Take a 100 g sample.
61.266 g F.
38.734 g C.
mols C = 38.734/12.015 = ?
mol F = 61.266/190 = ?
Find the ratio of the two elements to each other and calculate the molar mass of the empirical formula.
Then use PV = nRT and solve for n.
From n you can calculate the molar mass by n = grams/molar mass.
Finally, empirical mass x ? = molar mass; solve for ?, and the molecular formula is (empirical formula)?
you should end up with C2F2
A 0.02847 g sample of gas occupies 10.0-mL at 292.0 K and 1.10 atm. Upon further analysis, the compound is found to be 38.734% C and 61.266% F.
What is the MOLECULAR formula of the compound?
2 answers
I followed these steps:
1. Determine mass percentages as explained above. Based of the percentage values, I was able to determine that the mole ratio between C and F is 1:1
2. I used the PV=nRT equation to determine that n=4.5907e-4 moles.
I then divided the provided mass of 0.02847 by n to get the molar mass(g/mol)
3. Going back to the mass percentages that we did in step one, we determined the empirical formula, but not the molecular formula
4. Our the molar mass of our empirical formula (CF) is = to 31.009g/mol. However, the molar mass of ourmolecular formula is =62.016 based off of step 3. To calculate the molecular formula, divide 62.016g/mol by 31.009g/mol
5. That gives us a ratio of 2:1, molecular: empirical forumula; C2F2:CF
Final answer: C2F2
1. Determine mass percentages as explained above. Based of the percentage values, I was able to determine that the mole ratio between C and F is 1:1
2. I used the PV=nRT equation to determine that n=4.5907e-4 moles.
I then divided the provided mass of 0.02847 by n to get the molar mass(g/mol)
3. Going back to the mass percentages that we did in step one, we determined the empirical formula, but not the molecular formula
4. Our the molar mass of our empirical formula (CF) is = to 31.009g/mol. However, the molar mass of ourmolecular formula is =62.016 based off of step 3. To calculate the molecular formula, divide 62.016g/mol by 31.009g/mol
5. That gives us a ratio of 2:1, molecular: empirical forumula; C2F2:CF
Final answer: C2F2
0 answers