O: 28.59 g x 1 mole O/16 g = 1.79 moles OFe: 24.95 g x 1 mole/55.8 g = 0.447 moles Fe
Cr: 46.46 g x 1 mole/52 g = 0.893 moles Cr
Dividing through by 0.447 one gets 4O, 1Fe and 2Cr
Empirical formula = FeCr2O4
One atom of carbon, two of oxygen.
Convert mass percents to moles and then divide by the smallest mole value to get subscripts
P2o5
CCl4
Cr3Si2 is the empirical formula for a compound containing chromium and silicon an has 73.52 mass percent chromium.
Percent composition can be used to calculate the percentage of an element/compound in a mixture. From the percent composition, you can also find the empirical formula. And from the empirical formula you can find the actual molecular weight.
Not completely. The empirical formula of a substance can be determined from its percent composition, but a determination of molecular weight is needed to decide which multiple of the empirical formula represents the molecular formula.
C3 h3o
If it tells you to find the empirical formula when percent composition is given or if the mass of each element is given in a specific compound.
Because unlike the empirical formula, the molecular formula does not have to be the simplest ratio.If by chance you are given the percent composition of the elements in a substance, you could calculate the empirical formula and then the empirical formula's mass. However, the molecular formula equation is molecular formula= (empirical formula)n, where n is the mass of the molecular formula divided by the mass of the empirical formula. You would, therefore, need to know the mass belonging to the molecular formula, which you are not given.
One atom of carbon, two of oxygen.
Use the empirical formula. The numbers might be in percent composition, if that's the case convert to moles and proceed with the empirical formula.
Chi a+
Convert mass percents to moles and then divide by the smallest mole value to get subscripts
CHI3
Yes, if you have some additional information, such as the molecular weight. For instance, the molecules C2H4 and C4H8 have exactly the same percent composition, but they are very different molecules. So you need some other information to tell them apart than the percent composition.Answer ExpandedThis is kind of a trick question. By knowing the percent composition, you would easily be able to determine its empirical formula, but molecular formula is a bit different. The molecular formula is the actual number of atoms in a molecule, so in order to find the specific molecular formula of a substance, you would also need to know how many grams there is of that substance.(This explains the difference between C2H4 and C4H8)
P2o5