Predicting the Products of a Chemical Reaction

Part I: Formation Reactions

Predict the chemical formula of the product formed, then balance the entire equation.

(General Pattern: A + B -> AB)

1. Na + Cl2 -> ______________________

2. Mg + O2 -> ______________________

3. Al + Br2 -> ______________________

4. K + S -> ______________________

5. Li + N2 -> ______________________

6. H2 + O2 -> ______________________

Part II: Decomposition Reactions

Predict the products formed (break them into elements), then balance the entire equation. Remember your homonuclear diatomic elements!

(General Pattern: AB -> A + B)

7. H2O -> ______________________

8. HgO -> ______________________

9. MgCl2 -> ______________________

10. NI3 -> ______________________

11. Al2O3 -> ______________________

12. Ag2O -> ______________________

Part III: Combustion Reactions

Predict the products for the complete combustion of the following compounds, then balance the equation.

(General Pattern: carbohydrate + O2 -> CO2 + H2O)

13. CH4 + O2 -> ______________________ (Methane)

14. C3H8 + O2 -> ______________________ (Propane)

15. C6H12O6 + O2 -> ______________________ (Glucose)

16. C2H5OH + O2 -> ______________________ (Ethanol)

17. C4H10 + O2 -> ______________________ (Butane)

Part IV: Mixed Practice

Identify the reaction type (Synthesis, Decomposition, or Combustion), predict the products, and balance.

18. Ca + N2 -> ______________________

    Type: ______________________

19. FeS -> ______________________

    Type: ______________________

20. C8H18 + O2 -> ______________________

    Type: ______________________

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ANSWER KEY

Part I: Synthesis

1. 2Na + Cl2 -> 2NaCl

2. 2Mg + O2 -> 2MgO

3. 2Al + 3Br2 -> 2AlBr3

4. 2K + S -> K2S

5. 6Li + N2 -> 2Li3N

6. 2H2 + O2 -> 2H2O

Part II: Decomposition

7. 2H2O -> 2H2 + O2

8. 2HgO -> 2Hg + O2

9. MgCl2 -> Mg + Cl2

10. 2NI3 -> N2 + 3I2

11. 2Al2O3 -> 4Al + 3O2

12. 2Ag2O -> 4Ag + O2

Part III: Combustion

13. CH4 + 2O2 -> CO2 + 2H2O

14. C3H8 + 5O2 -> 3CO2 + 4H2O

15. C6H12O6 + 6O2 -> 6CO2 + 6H2O

16. C2H5OH + 3O2 -> 2CO2 + 3H2O

17. 2C4H10 + 13O2 -> 8CO2 + 10H2O

Part IV: Mixed Practice

18. Synthesis: 3Ca + N2 -> Ca3N2

19. Decomposition: 8FeS -> 8Fe + S8 (or Fe + S)

20. Combustion: 2C8H18 + 25O2 -> 16CO2 + 18H2O