1. USING MOLAR CONVERSIONS TO DETERMINE EMPIRICAL AND MOLECULAR FORMULAS

2. FORMULA OF A COMPOUND BASED ON CHARGES PREDICTION: WHAT WOULD BE THE FORMULA FOR MAGNESIUM OXIDE?

3. FORMULA BASED ON DATA: Empirical formula : Reduced formula. Ex. CH 2 O Molecular formula : Not reduced formula; must take into account atomic mass! Ex. C 6 H 12 O 6 Empirical or Molecular? P 2 Cl 6 PCl 5

4. APPLICATION: WHAT IS THE MOLECULAR FORMULA? A compound has a molecular mass of 132 g/mol and an empirical formula of CH 2 NO. What is its molecular formula?

5. HOW TO FIND EMPIRICAL FORMULA Change % to grams (if the % add up to 100) Change grams to moles. Find the mole ratio by dividing by the smallest number. Change the ratio to a whole # ratio by multiplying by a common multiple. Use the ratio as the subscripts in the formula.

6. FIND THE EMPIRICAL FORMULA OF: #1 A compound made of magnesium and oxygen that has a total mass of 5 grams and was made by reacting 3 grams of magnesium metal. #2 A compound made of 75% magnesium and 25% oxygen.

7. ANOTHER EMPIRICAL FORMULA QUESTION Example Problem #2 NutraSweet is 57.14% C, 6.16% H, 9.52% N, and 27.18% O. Calculate the empirical formula of NutraSweet (The molar mass of NutraSweet is 294.30 g/mol)

8. TO FIND MOLECULAR FORMULA: Find the mass of the empirical formula of the molecule. Divide the mass of the molecular formula weight by the empirical formula: If they are the same (1): the empirical formula IS the molecular formula. If they are not the same: multiple each atom in the empirical formula by the number you got when you divided.

9. MOLECULAR FORMULA OF NUTRASWEET (The molar mass of NutraSweet is 294.30 g/mol) What is the molecular formula?

10. EMPIRICAL AND MOLECULAR FORMULA The sample contains 2.143g of carbon and 0.358g of hydrogen. What is the total molecular weight of this compound? Find the empirical formula. Find the mass of the empirical formula. What is the molecular formula of this compound?