Molecular Formulas 
Solve the following problems.

1.  A compound is found to be 40.0 % carbon, 6.7 % hydrogen, and 53.5 % oxygen.  Its
    molecular mass is 60. grams per mole.  What is its molecular formula?

2.  A compound is 64.9 % carbon, 13.5 % hydrogen, and 21.6 % oxygen.  Its molecular
     mass is 74 grams per mole.  What is its molecular formula?

3.  A compound is 54.5 % carbon, 9.1 % hydrogen, and 36.4 % oxygen.  Its molecular mass
     is 88 grams per mole.  What is its molecular formula?

4.  If the molecular mass of an oxide of nitrogen is 108.  What is the molecular formula of a
     compound that contains 4.02 grams of nitrogen and 11.48 grams of oxygen?

5.         An organic compound is found to contain 92.25 % carbon and 7.75 % hydrogen.  If the
     molecular mass is 78, what is the molecular formula?

6.         The formula mass of a compound is 92.  Analysis of the compound shows that there are
     0.608 grams of nitrogen and 1.388 grams of oxygen.  What is the molecular formula of
     this compound?

7.         There are two different oxides of phosphorus.  Both oxides can exist in different forms
     depending on the temperature and pressure.  Calculate the empirical and molecular
     formulas from the following data:
           
(A) P:  56.4 %, O:  43.7 %, molecular mass = 220
           
(B) P:  43.6 %, O:  56.4 %, molecular mass = 284

8.  Nicotine is a compound that contains 74.0 % carbon, 8.7 % hydrogen, and 17.3 %
     nitrogen.  If the molecular mass is 162, what is the molecular formula?


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