1. MOLECULAR FORMULAS (here you will be using empirical to help you determine molecular formulas)

2. STEP 1: Find the empirical molar mass. Example 1: Find the molecular formula of a compound with empirical formula CH2 and a molar mass of 84.18g/mol.

3. STEP 2: Divide the molecular mass (GIVEN) by the empirical formula mass to get a mass multiple. Example 1: Find the molecular formula of a compound with empirical formula CH2 and a molar mass of 84.18g/mol.

4. STEP 3: Use the mass multiple to determine the molecular formula – multiply the empirical formula by the mass multiple. Example 1: Find the molecular formula of a compound with empirical formula CH2 and a molar mass of 84.18g/mol.

5. ...using percentage composition data. FINDING MOLECULAR FORMULAS...

6. ***Assume 100g of substance*** STEP 1: Find the amount of each in moles. Example 2: Determine the molecular formula of vitamin C (ascorbic acid). It contains 40.5% C, 4.6% H, and 54.5% O. Molar mass = 176.14g/mol.

7. STEP 2: Determine the simplest ratio. Example 2: Determine the molecular formula of vitamin C (ascorbic acid). It contains 40.5% C, 4.6% H, and 54.5% O. Molar mass = 176.14g/mol.

8. STEP 3: Find the lowest whole number ratio to determine the empirical formula. Example 2: Determine the molecular formula of vitamin C (ascorbic acid). It contains 40.5% C, 4.6% H, and 54.5% O. Molar mass = 176.14g/mol.

9. STEP 4: Determine the molar mass of C3H4O3. Example 2: Determine the molecular formula of vitamin C (ascorbic acid). It contains 40.5% C, 4.6% H, and 54.5% O. Molar mass = 176.14g/mol.

10. STEP 4: Determine the molar mass of C3H4O3. Example 2: Determine the molecular formula of vitamin C (ascorbic acid). It contains 40.5% C, 4.6% H, and 54.5% O. Molar mass = 176.14g/mol.

11. STEP 5&6: Solve for the mass multiple, then multiply the empirical formula by x. Example 2: Determine the molecular formula of vitamin C (ascorbic acid). It contains 40.5% C, 4.6% H, and 54.5% O. Molar mass = 176.14g/mol.

12. HOMEWORK: