Empirical Formulas Practice
1. A 1.0-gram sample of Barium was heated in a stream of oxygen gas. The resulting
oxide has a mass of 1.117 g. Find the empirical formula.
2. A 0.5998g sample of a compound has been shown to have the following makeup; find
the empirical formula:
Carbon: 0.2322; Hydrogen, 0.05848; Oxygen, 0.3091 (all in grams)
3. Analysis of a protein sample shows the element has the following percent
composition: Find the empirical formula.
N: 29.16%
C: 12.50%
H: 8.392%
O: 49.95%
4. If cobalt is heated in a sulfur bath, a sulfide is created with a mass that contains
55.06% Cobalt. Find the Empirical Formula.
5. A compound with the empirical formula CH has a molecular mass of near 78.
Determine the molecular formula.
6. With CH2O as an empirical formula, a compound has a molecular mass between 89
and 91. Determine the molecular formula
7. A compound found near a mining site is shown to contain copper (66.75%),
phosphorus (10.84%) and Oxygen (22.41%). Determine the empirical formula.
8. Alcoa Industries is the world’s largest producer of Aluminum metal. Aluminum ore
that is brought into Alcoa is a compound that contains roughly 15.8% Aluminum, 28.1%
sulfur, and 56.1% oxygen. What is the empirical formula?