1. Assume a 100g Sample:
* This makes calculations easier since percentages directly translate to grams.
* You have 40g of sulfur (S) and 60g of oxygen (O).
2. Convert Grams to Moles:
* Divide the mass of each element by its molar mass:
* Moles of S = 40g / 32.06 g/mol = 1.25 mol
* Moles of O = 60g / 16.00 g/mol = 3.75 mol
3. Find the Simplest Whole-Number Ratio:
* Divide each mole value by the smallest mole value (1.25 mol in this case):
* S: 1.25 mol / 1.25 mol = 1
* O: 3.75 mol / 1.25 mol = 3
4. Write the Empirical Formula:
* The ratio of sulfur to oxygen is 1:3.
* The empirical formula is SO₃.
