Is naproxin composed of 73.03% C, 6.13% H and 20.84% O (all percentages by mass)?
If the molecular weight is 230.26 g/mol
carbon = 73.03% = 230.26*73.03/100 = 168.15/12 = 14 carbons
Hydrogen = 6.13% = 230.26*6.13/100 = 14/1 = 14 Hydrogens
Oxygen = 20.84% = 230.26*20.84/100 = 47.98/16 = 3 Oxygen
Therefore, the empirical formula is C14H14O3
Naproxen chemical formula
90
Step 1: assume a 1 gram sample; the mass of C atoms will be 0.7303 g, the mass of H atoms will be 0.0613 g and the mass of O atoms will be 0.2084 g
Step 2: Convert grams of C atoms to moles of C atoms by dividing by the atomic mass of C. Convert the mass of H atoms to moles of H atoms. Convert the mass of O atoms to moles of O atoms (0.0608 mol C, 0.0608 mol H and 0.01303)
Step 3: Divide the moles of the C, H, and O atoms by the moles of the element with the fewest moles. This step will give you the ratio of atoms. (4.67C, 4.67H, 1O)
Step 4: Multiply everything by an integer (3X) to get integer results. (C14H14O3)
Step 5: Calculate the molar mass from the empirical formula. C14H14O3 = 230.26
Step 6: Determine the number of empirical formulas in the molecular formulas by dividing the molar mass of the molecular formula by the molar mass of the empirical formula. (230.26/230.26 = 1)
In this case, the empirical formula is the molecular formula.