Name______________
Percent Composition, Empirical, Molecular and
Hydrate Formulas Review
Calculate the percent composition of each element in the following compounds. Show all work on notebook
paper.
1. Fe3O4
2. Al2(SO4)3
Determine the empirical formula for the following. (Hint: simplify)
3. C2H4
4. C4H8O2
Determine the formula for each of the following. Show all work on notebook paper.
5. The compound styrene has a composition that is 92.25% carbon and 7.75% hydrogen.
6. MSG (monosodium glutamate) a common food additive has a composition of 35.5% carbon,
4.77% hydrogen, 8.29% nitrogen, 13.6% sodium, and 37.9% oxygen.
7. A 17.44 g sample of a hydrate of zinc sulfate is heated in a crucible to drive off all of the
water. After heating, the sample has a mass of 9.79g. What is the empirical formula for this
hydrate?
8. If the empirical formula for benzene is CH. What is the molecular formula for benzene with a
molar mass of 78?
9. Calculate the empirical and the molecular formula for a compound contains 18.8% sodium, 29.0%
chlorine, and 52.2% oxygen, by mass. If the molar mass of the compound is 122.44 g/mol, determine the
empirical and molecular formulas.