Chemistry - Stoichiometry - Empirical and molecular formulas - Finding Empirical Formula from % Composition

Step-by-step method. Problem: 'A compound is 40% C, 6.7% H, 53.3% O. Find empirical formula.' Step 1: Assume 100g sample → 40g C, 6.7g H, 53.3g O. Step 2: Convert to moles. C: 40÷12=3.33mol. H: 6.7÷1=6.7mol. O: 53.3÷16=3.33mol. Step 3: Divide by smallest. C: 3.33÷3.33=1. H: 6.7÷3.33=2. O: 3.33÷3.33=