1. Empirical and Molecular Formulas

2. Empirical vs. Molecular
Empirical formula: a formula that shows the simplest ratio of elements present in the compound
Molecular formula: formula that states the number of atoms in a particular molecule (can be reduced further)

3. Empirical or Molecular?
C6H12O6
CO2
C2H4
CH2O
CH2 NO CO
N2O2
SO2
S3O6

4. Question 1
Analysis of a sample of a covalent compound showed that it contained 85.6% carbon and 14.4% hydrogen. What is the empirical formula for this compound?

5. Question 2
What is the empirical formula for a compound containing 68.3% lead, 10.6% sulfur and the remainder oxygen?

6. Question 3
A compound contains sulfur, oxygen, and chlorine. Analysis shows that it contains 26.95% sulfur, and 59.61% chlorine. What is the simplest formula for this compound?

7. Question 4
A compound contains carbon, oxygen, and hydrogen. Analysis of a sample showed that it contained by mass % carbon and 4.96% hydrogen. What is the simplest formula for this compound?

8. What is the molecular formula of this compound?
A compound with an empirical formula of CO2 and a molar mass of 132 grams per mole.
What is the molecular formula of this compound?

9. Question 5
A compound contains 87.5% nitrogen and 12.5% hydrogen. Its molecular weight is found to be 32 g/mol. What is its molecular formula?

10. Question 6
A compound contains only carbon, hydrogen, and oxygen. Analysis of a sample showed that it contained 54.52% C and 9.15% H. Its molecular weight was determined to be approximately 88 g/mol. What is its molecular formula?

11. Empirical Formulas w/ Mass
Determine the empirical formula for a hydrocarbon if the complete combustion of a sample produces 5.28 g of CO2 and 1.62 g of H2O
C2H3

12. Practice 1
Determine the simplest formula for a hydrocarbon if the complete combustion of a sample produces 3.96 g of CO2 and 2.16 g of H2O.
C3H8

13. Practice 2
A compound is known to contain only carbon, hydrogen, and oxygen. If the complete combustion of a g sample of this compound produces g of CO2 and g of H2O, what is the empirical formula of this compound?
C3H4O3

14. Practice 3
The complete combustion of a g sample of a compound yielded g of CO2 and g of H2O. The molecular weight is determined to be approximately 60 g/mol. What is the molecular formula of this compound if it contains only carbon, hydrogen, and oxygen?
C2H4O2

15. Practice 4
41 g of CO2, 25 g of H2O, g of Total Compound containing C, H, and O
CH3O