Honors Chemistry                                                         Name________________________

Empirical Formula Worksheet

Mr. McAfoos                                                                   Period______ Date_____________

 

1.      A compound is comprised of 15.8% C and 84.2% sulfur. What is the empirical formula?

 

2.      A compound is comprised of 43.6% P and 56.4% O. What is the empirical formula?

 

3.      A compound is 92.3% C and 7.7% H. The GMM is 78.1 g/mol. What are the empirical and molecular formulas?

 

4.      Determine the empirical and molecular formulas for a compound that is 80% C and 20% H and has a GMM of 30 g/mol.

 

5.      Calculate the empirical formula for a compound that is 18.5% Na, 25.8% S, 19.3% O, and 36.4% H2O. (Note: the 19.3% O does NOT include the oxygen in the water. Note2: Treat the water as anything else…just use the GMM of water instead of an atomic mass to convert to moles.)

 

6.      Determine the percent composition of the following compounds:

a)      ammonium acetate.

b)      Lithium bromide

c)      Silver dichromate

d)      Phosphoric acid