1. The empirical formula of a compound with molecules containing 12 carbon atoms, 14 hydrogen atoms, and 6 oxygen atoms is __________.

A. C₁₂H₁₄O₆

B. C₆H₇O₃

C. CHO

D. CH₂O

E. C₂H₄O

2. Calculate the percent composition, by mass, of carbon in the following compounds: (use a calculator)

Cocaine, C₁₇H₂₁NO₄

Vancomycin, C₅₅H₇₅Cl₂N₉O₂₄

3. What is the molecular formula of each of the following compounds?

Empirical formula CH₂, molar mass = 84 g/mol

Empirical formula HCO₂, molar mass = 90.0 g/mol