Question

directions: label the following reactions as synthesis (s), decomposition (d), single replacement (sr), double replacement (dr) and combustion (c), then balance. place a \b\ at the end that are balanced as written.

1. nacl → na + cl₂
2. na + cl₂ → nacl
3. c₂h₄ + o₂ → co₂ + h₂o
4. h₂o → h₂ + o₂
5. h₂ + o₂ → h₂o
6. c₈h₁₈ + o₂ → co₂ + h₂o
7. naoh + hcl → hoh + nacl
8. na + hcl → h₂ nacl
9. k + cl₂ → kcl
10. k + agcl → ag + kcl
11. c₆h₁₂ + o₂ → co₂ + h₂o
12. ca + s → cas
13. koh + hno₃ → hoh + kno₃
14. al + o₂ → al₂o₃
15. hgo → hg + o₂
16. naoh + h₂so₄ → na₂so₄ + h₂o
17. fe + o₂ → fe₂o₃
18. c₆h₈ + o₂ → co₂ + h₂o
19. pb(no₃)₂ + k₂cro₄ →pbcro₄ + kno₃
20. h₂ + n₂ → nh₃

Explanation:

Step1: Identify reaction type for NaCl → Na + Cl₂

This is a decomposition reaction as one compound breaks into two elements. Unbalanced.

Step2: Balance the equation

2NaCl → 2Na + Cl₂

Step3: Identify reaction type for Na + Cl₂ → NaCl

This is a synthesis reaction as two elements combine to form a compound. Unbalanced.

Step4: Balance the equation

2Na + Cl₂ → 2NaCl

Step5: Identify reaction type for C₂H₄ + O₂ → CO₂ + H₂O

This is a combustion reaction as a hydrocarbon reacts with oxygen. Unbalanced.

Step6: Balance the equation

C₂H₄ + 3O₂ → 2CO₂ + 2H₂O

Step7: Identify reaction type for H₂O → H₂ + O₂

This is a decomposition reaction. Unbalanced.

Step8: Balance the equation

2H₂O → 2H₂ + O₂

Step9: Identify reaction type for H₂ + O₂ → H₂O

This is a synthesis reaction. Unbalanced.

Step10: Balance the equation

2H₂ + O₂ → 2H₂O

Step11: Identify reaction type for C₈H₁₈ + O₂ → CO₂ + H₂O

This is a combustion reaction. Unbalanced.

Step12: Balance the equation

2C₈H₁₈ + 25O₂ → 16CO₂ + 18H₂O

Step13: Identify reaction type for NaOH + HCl → HOH + NaCl

This is a double - replacement reaction (HOH is H₂O). Balanced as written (B).

Step14: Identify reaction type for Na + HCl → H₂ + NaCl

This is a single - replacement reaction. Unbalanced.

Step15: Balance the equation

2Na + 2HCl → H₂ + 2NaCl

Step16: Identify reaction type for K + Cl₂ → KCl

This is a synthesis reaction. Unbalanced.

Step17: Balance the equation

2K + Cl₂ → 2KCl

Step18: Identify reaction type for K + AgCl → Ag + KCl

This is a single - replacement reaction. Balanced as written (B).

Step19: Identify reaction type for C₆H₁₂ + O₂ → CO₂ + H₂O

This is a combustion reaction. Unbalanced.

Step20: Balance the equation

C₆H₁₂ + 9O₂ → 6CO₂ + 6H₂O

Step21: Identify reaction type for Ca + S → CaS

This is a synthesis reaction. Balanced as written (B).

Step22: Identify reaction type for KOH + HNO₃ → HOH + KNO₃

This is a double - replacement reaction. Balanced as written (B).

Step23: Identify reaction type for Al + O₂ → Al₂O₃

This is a synthesis reaction. Unbalanced.

Step24: Balance the equation

4Al + 3O₂ → 2Al₂O₃

Step25: Identify reaction type for HgO → Hg + O₂

This is a decomposition reaction. Unbalanced.

Step26: Balance the equation

2HgO → 2Hg + O₂

Step27: Identify reaction type for NaOH + H₂SO₄ → Na₂SO₄ + H₂O

This is a double - replacement reaction. Unbalanced.

Step28: Balance the equation

2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O

Step29: Identify reaction type for Fe + O₂ → Fe₂O₃

This is a synthesis reaction. Unbalanced.

Step30: Balance the equation

4Fe + 3O₂ → 2Fe₂O₃

Step31: Identify reaction type for C₆H₈ + O₂ → CO₂ + H₂O

This is a combustion reaction. Unbalanced.

Step32: Balance the equation

C₆H₈ + 8O₂ → 6CO₂ + 4H₂O

Step33: Identify reaction type for Pb(NO₃)₂ + K₂CrO₄ → PbCrO₄ + KNO₃

This is a double - replacement reaction. Unbalanced.

Step34: Balance the equation

Pb(NO₃)₂ + K₂CrO₄ → PbCrO₄ + 2KNO₃

Step35: Identify reaction type for H₂ + N₂ → NH₃

This is a synthesis reaction. Unbalanced.

Step36: Balance the equation

3H₂ + N₂ → 2NH₃

Answer:

1. D, 2NaCl → 2Na + Cl₂
2. S, 2Na + Cl₂ → 2NaCl
3. C, C₂H₄ + 3O₂ → 2CO₂ + 2H₂O
4. D, 2H₂O → 2H₂ + O₂
5. S, 2H₂ + O₂ → 2H₂O
6. C, 2C₈H₁₈ + 25O₂ → 16CO₂ + 18H₂O
7. DR, B, NaOH + HCl → H₂O + NaCl
8. SR, 2Na + 2HCl → H₂ + 2NaCl
9. S, 2K + Cl₂ → 2KCl
10. SR, B, K + AgCl → Ag + KCl
11. C, C₆H₁₂ + 9O₂ → 6CO₂ + 6H₂O
12. S, B, Ca + S → CaS
13. DR, B, KOH + HNO₃ → H₂O + KNO₃
14. S, 4Al + 3O₂ → 2Al₂O₃
15. D, 2HgO → 2Hg + O₂
16. DR, 2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O
17. S, 4Fe + 3O₂ → 2Fe₂O₃
18. C, C₆H₈ + 8O₂ → 6CO₂ + 4H₂O
19. DR, Pb(NO₃)₂ + K₂CrO₄ → PbCrO₄ + 2KNO₃
20. S, 3H₂ + N₂ → 2NH₃