Empirical and Molecular Formulas

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)

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

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?

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

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?

Question 4 A compound contains carbon, oxygen, and hydrogen. Analysis of a sample showed that it contained by mass 68.83% carbon and 4.96% hydrogen. What is the simplest formula for this compound?

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?

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?

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?

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

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

Practice 2 A compound is known to contain only carbon, hydrogen, and oxygen. If the complete combustion of a 0.150 g sample of this compound produces 0.225 g of CO2 and 0.0614 g of H2O, what is the empirical formula of this compound? C3H4O3

Practice 3 The complete combustion of a 0.2864 g sample of a compound yielded 0.420 g of CO2 and 0.172 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

Practice 4 41 g of CO2, 25 g of H2O, 29.90 g of Total Compound containing C, H, and O CH3O