Percent composition

Find the percent composition of calcium nitrate.

Step 1: write the formula: Ca 2+ NO31- Ca(NO3)2

Step 2: find molar mass Step 3: divide by molar mass and

multiply by 1001 mol Ca x 40.08g = 40.08 g/mol / 164.10 g/mol x 100 = 24.42 % Ca

2 mol N x 14.01g = 28.02 g/mol / 164.10 g/mol x 100 = 17.07 % N

6 mol O x 16.00g = 96.00 g/mol / 164.10 g/mol x 100 = 58.50 % O

164.10 g/mol

Assignment

Determine the percent composition for the following:

1. Ibuprofen C13H18O2

2. Beryllium acetate Be(C2H3O2)2

3. Dinitrogen hexoxide N2O6

4. Aluminum chromate Al2(CrO4)3

5. Potassium sulfate K2SO4