A 0.02882 g sample of gas occupies 10.0-mL at 288.5 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?
What is the geometry shape around each carbon atom?
Polar or Nonpolar?
Use PV = nRT and solve for n = numbre of mols. Substitute into n = grams/molar mass. You know mols and grams, solve fo rmolar mass. Use that number later.
Take a 100 g sample which gives you
38.734 g C and 61.266 g F. Convert to mols.
38.734/12 = ?
61.266/19 = ?
Find the ratio of C to F with the smallest number being 1.00. The easy way to do that is to divide the smaller number by itself; then divide the other number by the same small number. That gives you the empirical formula.
Calculate the mass of the empirical formula and substitute into
empirical formula x ?number = molar mass from above and round ?number to a whole number.
The molecular formula is (CxHy)?
Post your work if you get stuck.
For n I got 26.18 mols. For the mass I got 31 because it was CF.
26.18 is not right. CF is the empirical formula. The empirical mass is not 31. You need the molar mass from mols and grams.
The moles of C is 3.227. The moles of F is 3.224. Therefore the empirical formula is CF. How would I find the empirical mass? Your explanation is confusing.
Yes, I said the empirical formula of CF is correct. My error for empirical mass; it is 12 + 19 = 31 as you noted.
Here is how you do the molar mass.
PV = nRT
P = 1.10 atm
V = 10.0 mL = 0.0100 L
n = solve for this
R = 0.08206 L*atm/mol*K
T = 288.5 K.
Solve for n = about 5E-4 but that is just a close estimate.
Then n = grams/molar mass and
about 5E-4 = 0.02882/molar mass.
Solve for molar mass which is approximately 60.
The molecular formula then is
empirical formula x ? number = molar mass
31 x ? = 60
? = about 2 when rounded to a whole number; theefore, the molecular formula is
(empirical formula)2 or
C2F2
You should go through and confirm those numbers since they are just estimates on my part.
To determine the molecular formula of the compound, we can start by finding the number of moles of each element in the given sample.
1. Calculate the number of moles of carbon (C):
First, convert the mass of carbon to moles using the molar mass of carbon (12.01 g/mol):
0.02882 g / 12.01 g/mol = 0.002400 mol of C
2. Calculate the number of moles of fluorine (F):
Similarly, convert the mass of fluorine to moles using the molar mass of fluorine (19.00 g/mol):
(0.38734 g F / 100) * (1 mol F / 19.00 g F) = 0.02039 mol of F
Next, we need to find the mole ratio between carbon and fluorine to determine the empirical formula of the compound.
3. Find the mole ratio between C and F:
Divide the number of moles of each element by the smaller number of moles (in this case, carbon):
0.002400 mol of C / 0.002400 mol of C = 1
0.02039 mol of F / 0.002400 mol of C ≈ 8.495
The mole ratio between C and F is approximately 1:8.495, which we can round to 1:8.
4. Determine the empirical formula:
The empirical formula represents the simplest whole-number ratio of atoms in the compound. Using the obtained mole ratio:
Empirical formula = C1F8
To find the molecular formula, we need to know the molar mass of the compound. Unfortunately, this information is not given in the question. However, we can still determine the molecular formula by making an assumption.
5. Assume molar mass:
For the molecular formula, let's assume the molar mass is 100 g/mol (just for calculations). You can replace this value with the actual molar mass if given in the problem.
6. Calculate the molar mass of the empirical formula:
The molar mass of the empirical formula C1F8 is:
(1 * 12.01 g/mol) + (8 * 19.00 g/mol) = 160.08 g/mol
7. Find the ratio of assumed molar mass to the molar mass of the empirical formula:
Assumed molar mass / Molar mass of the empirical formula:
100 g/mol / 160.08 g/mol ≈ 0.624
8. Multiply the subscripts in the empirical formula by the ratio from step 7:
C1F8 * 0.624 ≈ C0.624F4.992
Rounding the subscripts to the nearest whole number, we get the molecular formula of the compound as C1F5.
Regarding the geometry shape around each carbon atom, we need additional information about the compound's structure, such as the type of bonding (single, double, or triple) and the arrangement of atoms. Without this information, it is not possible to determine the geometry shape precisely.
For the polar or nonpolar nature of the compound, it is difficult to determine without knowing the compound's complete structure. The arrangement of atoms and presence of any polar bonds or symmetry in the molecule will determine its polarity.