Percent Composition Practice

Calculate the percent composition the elements or groups indicated in the following compounds: (answers at the bottom)

 

1) OXYGEN in Sulfuric acid  H₂SO₄ 

2) COPPER in Copper (II) chloride CuCl₂

3)  WATER in Calcium Chloride dihydrate CaCl₂•2H₂O

4) SULFATE IONS in Sodium sulfate Na₂SO₄

5) ANHYDROUS SALT  (CuSO₄) in copper (II) sulfate pentahydrate CuSO₄•5H₂O

6) CARBON in Hexane C₆H₁₄

7) NITRATE IONS  (NO₃^–)in Aluminum nitrate Al(NO₃)₃

8) AMMONIUM IONS (NH₄⁺)in Ammonium Phosphate (NH₄)₃PO₄

9) CALCIUM in Calcium Phosphate Ca₃(PO₄)₂

10) ALUMINUM in Aluminum silicate Al₂(SiO₃)₃

answers:

 

1. 65.31%
2. 47.40%
3. 24.49%
4. 67.60%
5. 64.00%
6. 83.72%
7. 87.32%
8. 36.24%
9.  38.71%
10. 19.15%