1. M EASUREMENTS AND C ALCULATIONS IN CHEMISTRY - M OLECULAR FORMULAS Dr. Chin Chu Chemistry River Dell High School

2. D EFINITION : Molecular Formula - of a chemical compound identifies the number of each type of atom in a molecule.

3. BACKGROUND

4. E XAMPLES

5. T HE PROCESS

6. A compound was composed of carbon (85.7% by mass) and hydrogen (14.3% by mass) with a molecular weight (molar mass) of 64.0 g/mol. What is the molecular formula for this compound? M OLECULAR FORMULA E XAMPLES

7. A compound was analyzed to be composed of nitrogen and oxygen. Percent composition of each element is 30.4% (nitrogen) and 69.6% (oxygen). Molar mass of the compound was measured to be 92.0g/mol. What is the molecular formula for the compound? What is the molecular formula for a compound consists of carbon(25.9% by mass) and hydrogen (74.1% by mass) and a molecular weight (molar mass) of 78.0g/mol.? What is the molecular formula for a compound consists of carbon (32.7% by mass), hydrogen (2.0% by mass), and oxygen (65.3% by mass) with a molar mass (molecular weight) of 180.0 g/mol.? M OLECULAR FORMULA – EXERCISE PROBLEMS

8. [N 2 O 4 ] [C 6 H 6 ] [C 6 H 12 O 6 ] E MPIRICAL FORMULA – A NSWERS