1. Percent Composition Empirical & Molecular Formulas

2. Percent Composition The percent by mass of each element in the compound

3. Percent Composition Example 1 Determine the percent composition of caclium carbonate, CaCO 3.

5. Percent Composition Example 2 Determine the percent composition of magnesium nitrate, Mg(NO 3 ) 2.

7. Empirical Formula A chemical formula showing the simplest ratio of elements in a compound

8. Molecular Formula A formula that shows the actual number of each element in a compound.

9. Empirical & Molecular Formula Ethyne, C 2 H 2 Empirical Formula Molecular Formula Styrene, C 8 H 8 Empirical Formula Molecular Formula

10. Empirical Formula Example 3 A compound is found to contain 25.9% nitrogen and 74.1% oxygen. Determine the empirical formula.

12. Empirical Formula Example 4 What is the empirical formula for a compound which contains 67.1% zinc and the rest oxygen?

14. Empirical Formula Example 5 Find the empirical formula of a compound that contains 2.374% H, 14.14% C, and 83.48% Cl.

16. Empirical Formula Example 6 A compound contains 57.54% C, 3.45% H, and 39.01% F. What is its empirical formula?

18. Molecular Formula Example 7 Calculate the molecular formula of a compound whose molar mass is 60.0 g/mol and the empirical formula is CH 4 N.

20. Molecular Formula Example 8 A compound is found to contain 50.05 % sulfur and 49.95 % oxygen by weight. What is the empirical formula for this compound? The molecular weight for this compound is 64.07 g/mol. What is its molecular formula?