Empirical & Molecular
Formulas Worksheet
Key
1. A compound used in fluoroscopy to obtain images of
internal organs in the human body contains 1.67g
of cerium, Ce, and 4.54g of iodine, I. What is the
empirical formula of this compound?
2. Methylpropene is used in the production of synthetic
rubber. Calculate the empirical formula of this
compound that contains 0.556g of carbon, C, and
0.0933g of hydrogen, H.
3. Benzoic acid is a compound used as a food preservative.
It contains 68.8%C, 4.95%H, and 26.2%O by mass.
What is the empirical formula of this compound?
4. Freon is a gaseous compound used in refrigeration and
air conditioning systems. It contains 9.93% carbon,
58.6% chlorine, and 31.4% fluorine by mass. Find
the empirical formula of Freon?
5. Dichloroacetic acid is corrosive to the skin and has been
used to remove blemishes. What is the molecular formula
of dichloroacetic acid, if the empirical formula is CHOCl
and the molecular mass is 129 amu?
S
6. What is the molecular formula of cyanuric chloride, a compound
used in the production of some dyes, if the empirical formula
if CClN and the molecular mass is 184.5 amu.
7. Ascorbic acid, also known as vitamin C, has a percentage
composition of 40.9% carbon, 4.58% hydrogen, and 54.5%
oxygen. What is the molecular formula of ascorbic acid given
that it has a molecular mass of 176.1 amu?
8. Aspirin contains 60.0% carbon, 4.48% hydrogen, and
35.5% oxygen. It has a molecular mass of 180.0 amu.
What is the molecular formula of aspirin?