00:01
To determine the empirical formula of the compound, we need to know the moles of each element in the compound.
00:08
To get the moles, we need to know the mass.
00:11
If we have mass percentages, percent composition, and we assume that we have 100 grams of the compound, then the percentages become masses.
00:21
So if we have 38 .7 grams of carbon, we'll divide that by the molar mass of carbon to get moles carbon.
00:28
If it's 9 .74 % hydrogen, that's the grams of hydrogen we have, which we divide by the molar mass to get moles of hydrogen.
00:38
And if it's 51 .6 % oxygen, assuming 100 grams of the compound, we have 51 .6 grams of oxygen, which will convert into moles of oxygen by dividing by the molar mass of oxygen.
00:52
These values could serve as subscripts, but they're not very conventional, so we need to get whole numbers to get whole numbers...