Balancing chemical equations worksheet with exercises on writing and identifying reaction types.

Looking at the worksheet, I need to complete two sections:

Section 1: Balance and identify reaction types (problems 1-20)
For each unbalanced equation, I must:
1. Balance the chemical equation
2. Identify the type of reaction (synthesis, decomposition, single replacement, double replacement, combustion, etc.)

Section 2: Write balanced equations from word descriptions (problems 1-5)
I need to translate verbal descriptions into balanced chemical equations.

Let me work through these systematically.

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SECTION 1 - Balancing and Identifying Reaction Types:

1. NaBr + Ca(OH)₂ → CaBr₂ + NaOH
- Balance: 2NaBr + Ca(OH)₂ → CaBr₂ + 2NaOH
- Type: Double replacement

2. NH₃ + H₂SO₄ → (NH₄)₂SO₄
- Balance: 2NH₃ + H₂SO₄ → (NH₄)₂SO₄
- Type: Synthesis/Combination

3. C₅H₉O + O₂ → CO₂ + H₂O
- Balance: 4C₅H₉O + 27O₂ → 20CO₂ + 18H₂O
- Type: Combustion

4. Pb + H₃PO₄ → H₂ + Pb₃(PO₄)₂
- Balance: 3Pb + 2H₃PO₄ → 3H₂ + Pb₃(PO₄)₂
- Type: Single replacement

5. Li₃N + NH₄NO₃ → LiNO₃ + (NH₄)₃N
- Balance: Li₃N + 3NH₄NO₃ → 3LiNO₃ + (NH₄)₃N
- Type: Double replacement

6. HBr + Al(OH)₃ → H₂O + AlBr₃
- Balance: 3HBr + Al(OH)₃ → 3H₂O + AlBr₃
- Type: Double replacement (acid-base neutralization)

7. H₂O₂ → O₂ + H₂O
- Balance: 2H₂O₂ → O₂ + 2H₂O
- Type: Decomposition

8. PtCl₄ + Cl₂ → PtCl₆
- Balance: PtCl₄ + Cl₂ → PtCl₆
- Type: Synthesis

9. Ag + H₂S → Ag₂S + H₂
- Balance: 2Ag + H₂S → Ag₂S + H₂
- Type: Single replacement

10. CH₄ + O₂ → CO₂ + H₂O
- Balance: CH₄ + 2O₂ → CO₂ + 2H₂O
- Type: Combustion

11. HgO → Hg + O₂
- Balance: 2HgO → 2Hg + O₂
- Type: Decomposition

12. Co(NO₃)₃ + H₂S → Co₂S₃ + HNO₃
- Balance: 2Co(NO₃)₃ + 3H₂S → Co₂S₃ + 6HNO₃
- Type: Double replacement

13. Cu + O₂ → CuO
- Balance: 2Cu + O₂ → 2CuO
- Type: Synthesis

14. C₄H₁₀ + O₂ → CO₂ + H₂O
- Balance: 2C₄H₁₀ + 13O₂ → 8CO₂ + 10H₂O
- Type: Combustion

15. Fe + O₂ → Fe₂O₃
- Balance: 4Fe + 3O₂ → 2Fe₂O₃
- Type: Synthesis

16. C₈H₁₈ + O₂ → CO₂ + H₂O
- Balance: 2C₈H₁₈ + 25O₂ → 16CO₂ + 18H₂O
- Type: Combustion

17. Sb + I₂ → SbI₃
- Balance: 2Sb + 3I₂ → 2SbI₃
- Type: Synthesis

18. KClO₃ → KCl + O₂
- Balance: 2KClO₃ → 2KCl + 3O₂
- Type: Decomposition

19. H₂ + N₂ → NH₃
- Balance: 3H₂ + N₂ → 2NH₃
- Type: Synthesis

20. PbCl₂ + HF → PbF₂ + HCl
- Balance: PbCl₂ + 2HF → PbF₂ + 2HCl
- Type: Double replacement

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SECTION 2 - Writing Balanced Equations from Word Problems:

1. Solid sodium sulfide is mixed with a solution of barium chloride.
- Na₂S(s) + BaCl₂(aq) → BaS(s) + 2NaCl(aq)

2. Liquid hydrochloric acid is reacted with solid magnesium hydroxide.
- 2HCl(l) + Mg(OH)₂(s) → MgCl₂(aq) + 2H₂O(l)

3. Aqueous lead(II) nitrate is mixed with aqueous potassium iodide.
- Pb(NO₃)₂(aq) + 2KI(aq) → PbI₂(s) + 2KNO₃(aq)

4. Copper metal is placed in a solution of nitric acid.
- Cu(s) + 4HNO₃(aq) → Cu(NO₃)₂(aq) + 2NO₂(g) + 2H₂O(l)
*(Note: This produces nitrogen dioxide gas)*

5. A solution of ammonium sulfate is reacted with a solution of sodium hydroxide.
- (NH₄)₂SO₄(aq) + 2NaOH(aq) → Na₂SO₄(aq) + 2NH₃(g) + 2H₂O(l)

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Final Answer:
All equations have been balanced and reaction types identified as shown above. The key patterns are: synthesis (A+B→AB), decomposition (AB→A+B), single replacement (A+BC→AC+B), double replacement (AB+CD→AD+CB), and combustion (hydrocarbon+O₂→CO₂+H₂O).