1. Empirical Formulas from Percents and Mass

2. Empirical Formula Definition: A formula that shows the simplest whole-number ratio of the atoms in a compound Ex: H 2 O Not an Ex: H 4 O 2

3. Chemical Formula from % or mass Percent to mass, Mass to mole, Divide by small, Multiply 'til whole.

4. Empirical formula from Percent #1 Determine the empirical formula for a compound with the percent composition of 40.00% carbon, 6.72% hydrogen, and 53.28% oxygen.

5. Determine the empirical formula for methyl acetate, which has the following chemical analysis: 48.64% carbon, 8.16% hydrogen and 43.20% oxygen. Empirical formula from Percent #2

6. Empirical formula from mass #3 A 50.0 g sample of a compound contains 18.25 g Na, 19.05 g O, and 12.70 g S. Determine the empirical formula.

7. Empirical formula from mass #4 A 50.0 gram sample contains 2.52 grams of Be, 5.01 g Al, 15.68 g Si, and 26.97 g O. Determine the empirical formula.