49 Balancing Chemical Equations Worksheets [with Answers] - Free Printable
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Step-by-step solution for: 49 Balancing Chemical Equations Worksheets [with Answers]
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Step-by-step solution for: 49 Balancing Chemical Equations Worksheets [with Answers]
Here is the complete solution to Worksheet: Writing and Balancing Chemical Reactions, including balanced equations, reaction types, and explanations.
---
## Part 1: Balance the following equations and indicate the type of reaction
Unbalanced: Cu(s) + O₂(g) → CuO(s)
Balanced: 2Cu(s) + O₂(g) → 2CuO(s)
✔ *Type:* Formation (two elements combine to form one compound)
---
Unbalanced: H₂O(l) → H₂(g) + O₂(g)
Balanced: 2H₂O(l) → 2H₂(g) + O₂(g)
✔ *Type:* Decomposition (one compound breaks into two elements)
---
Unbalanced: Fe(s) + H₂O(g) → H₂(g) + Fe₃O₄(s)
Balanced: 3Fe(s) + 4H₂O(g) → 4H₂(g) + Fe₃O₄(s)
✔ *Type:* Single Replacement (Fe displaces H from H₂O)
---
Unbalanced: AsCl₃(aq) + H₂S(aq) → As₂S₃(s) + HCl(aq)
Balanced: 2AsCl₃(aq) + 3H₂S(aq) → As₂S₃(s) + 6HCl(aq)
✔ *Type:* Double Replacement (ions swap partners; precipitate forms)
---
Unbalanced: CuSO₄·5H₂O(s) → CuSO₄(s) + H₂O(g)
Balanced: CuSO₄·5H₂O(s) → CuSO₄(s) + 5H₂O(g)
✔ *Type:* Decomposition (hydrated salt loses water molecules)
---
Unbalanced: Fe₂O₃(s) + H₂(g) → Fe(s) + H₂O(l)
Balanced: Fe₂O₃(s) + 3H₂(g) → 2Fe(s) + 3H₂O(l)
✔ *Type:* Single Replacement (H₂ reduces Fe₂O₃ to Fe)
---
Unbalanced: CaCO₃(s) → CaO(s) + CO₂(g)
Balanced: CaCO₃(s) → CaO(s) + CO₂(g)
✔ *Type:* Decomposition (carbonate decomposes to oxide + CO₂)
---
Unbalanced: Fe(s) + S₈(s) → FeS(s)
Balanced: 8Fe(s) + S₈(s) → 8FeS(s)
✔ *Type:* Formation (elements combine to form a compound)
---
Unbalanced: H₂S(aq) + KOH(aq) → H₂O(l) + K₂S(aq)
Balanced: H₂S(aq) + 2KOH(aq) → 2H₂O(l) + K₂S(aq)
✔ *Type:* Double Replacement / Acid-Base Neutralization
---
Unbalanced: NaCl(l) → Na(l) + Cl₂(g)
Balanced: 2NaCl(l) → 2Na(l) + Cl₂(g)
✔ *Type:* Decomposition (electrolysis of molten salt)
---
Unbalanced: Al(s) + H₂SO₄(aq) → H₂(g) + Al₂(SO₄)₃(aq)
Balanced: 2Al(s) + 3H₂SO₄(aq) → 3H₂(g) + Al₂(SO₄)₃(aq)
✔ *Type:* Single Replacement (Al displaces H from acid)
---
Unbalanced: H₃PO₄(aq) + NH₄OH(aq) → H₂O(l) + (NH₄)₃PO₄(aq)
Balanced: H₃PO₄(aq) + 3NH₄OH(aq) → 3H₂O(l) + (NH₄)₃PO₄(aq)
✔ *Type:* Double Replacement / Acid-Base Neutralization
---
Unbalanced: C₃H₈(g) + O₂(g) → CO₂(g) + H₂O(l)
Balanced: C₃H₈(g) + 5O₂(g) → 3CO₂(g) + 4H₂O(l)
✔ *Type:* Hydrocarbon Combustion
---
Unbalanced: Al(s) + O₂(g) → Al₂O₃(s)
Balanced: 4Al(s) + 3O₂(g) → 2Al₂O₃(s)
✔ *Type:* Formation
---
Unbalanced: CH₄(g) + O₂(g) → CO₂(g) + H₂O(l)
Balanced: CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(l)
✔ *Type:* Hydrocarbon Combustion
---
Unbalanced: K₂SO₄(aq) + BaCl₂(aq) → KCl(aq) + BaSO₄(s)
Balanced: K₂SO₄(aq) + BaCl₂(aq) → 2KCl(aq) + BaSO₄(s)
✔ *Type:* Double Replacement (precipitation reaction)
---
Unbalanced: C₅H₁₂(l) + O₂(g) → CO₂(g) + H₂O(g)
Balanced: C₅H₁₂(l) + 8O₂(g) → 5CO₂(g) + 6H₂O(g)
✔ *Type:* Hydrocarbon Combustion
---
Unbalanced: Ca(OH)₂(aq) + NH₄Cl(aq) → NH₄OH(aq) + CaCl₂(aq)
Balanced: Ca(OH)₂(aq) + 2NH₄Cl(aq) → 2NH₄OH(aq) + CaCl₂(aq)
✔ *Type:* Double Replacement
> Note: In reality, NH₄OH decomposes to NH₃(g) + H₂O(l), but as written, we balance as is.
---
Unbalanced: V₂O₅(s) + Ca(s) → CaO(s) + V(s)
Balanced: V₂O₅(s) + 5Ca(s) → 5CaO(s) + 2V(s)
✔ *Type:* Single Replacement (Ca reduces vanadium oxide)
---
Unbalanced: Na(s) + ZnI₂(aq) → NaI(aq) + Zn(s)
Balanced: 2Na(s) + ZnI₂(aq) → 2NaI(aq) + Zn(s)
✔ *Type:* Single Replacement (Na displaces Zn)
---
Unbalanced: C₇H₆O₃(l) + O₂(g) → CO₂(g) + H₂O(l)
*(This is salicylic acid — C₇H₆O₃)*
Balanced: C₇H₆O₃(l) + 7O₂(g) → 7CO₂(g) + 3H₂O(l)
✔ *Type:* Combustion (organic compound burns in oxygen)
---
Unbalanced: Ca(s) + N₂(g) → Ca₃N₂(s)
Balanced: 3Ca(s) + N₂(g) → Ca₃N₂(s)
✔ *Type:* Formation
---
Unbalanced: Fe₂O₃(s) + H₂(g) → Fe(s) + H₂O(l)
Balanced: Fe₂O₃(s) + 3H₂(g) → 2Fe(s) + 3H₂O(l)
✔ *Type:* Single Replacement (same as f — reduction by H₂)
---
Unbalanced: C₁₅H₃₀(l) + O₂(g) → CO₂(g) + H₂O(g)
Balanced: 2C₁₅H₃₀(l) + 45O₂(g) → 30CO₂(g) + 30H₂O(g)
✔ *Type:* Hydrocarbon Combustion
---
Unbalanced: BN(s) + F₂(g) → BF₃(s) + N₂(g)
Balanced: 2BN(s) + 3F₂(g) → 2BF₃(s) + N₂(g)
✔ *Type:* Single Replacement (F displaces N? Actually, it’s a redox reaction — can classify as “Other” or “Combination/Redox”)
> Since B and N are covalently bonded, and F₂ oxidizes both, this is best called “Other” (redox).
---
Unbalanced: C₁₂H₂₆(l) + O₂(g) → CO₂(g) + H₂O(g)
Balanced: 2C₁₂H₂₆(l) + 37O₂(g) → 24CO₂(g) + 26H₂O(g)
✔ *Type:* Hydrocarbon Combustion
---
## Part 2: Predict products, states, type, and balance
---
Reaction: Pb(NO₃)₂(aq) + 2NaI(aq) → PbI₂(s) + 2NaNO₃(aq)
✔ *Type:* Double Replacement / Precipitation
*Note:* PbI₂ is a bright yellow precipitate.
---
Reaction: 2ZnS(s) + 3O₂(g) → 2ZnO(s) + 2SO₂(g)
✔ *Type:* Combustion / Redox
*Note:* Metal sulfide reacts with O₂ to form metal oxide and SO₂.
---
Reaction: 2C₄H₁₀(l) + 13O₂(g) → 8CO₂(g) + 10H₂O(g)
✔ *Type:* Hydrocarbon Combustion
---
Reaction: Ba(OH)₂(aq) + 2HCl(aq) → BaCl₂(aq) + 2H₂O(l)
✔ *Type:* Double Replacement / Acid-Base Neutralization
---
Reaction: Cu(s) + 2AgNO₃(aq) → Cu(NO₃)₂(aq) + 2Ag(s)
✔ *Type:* Single Replacement
*Note:* Cu displaces Ag⁺ because Cu is more reactive than Ag.
---
Reaction: S(s) + O₂(g) → SO₂(g)
✔ *Type:* Formation / Combustion
---
Reaction: Al₂(SO₄)₃(aq) + 3Ca(OH)₂(aq) → 2Al(OH)₃(s) + 3CaSO₄(s)
✔ *Type:* Double Replacement / Precipitation
*Note:* Both Al(OH)₃ and CaSO₄ may precipitate (CaSO₄ is slightly soluble).
---
Reaction: Zn(s) + H₂SO₄(aq) → ZnSO₄(aq) + H₂(g)
✔ *Type:* Single Replacement
---
Reaction: 2Al(s) + 3Cl₂(g) → 2AlCl₃(s)
✔ *Type:* Formation
---
Reaction: C₁₂H₂₂O₁₁(s) + 12O₂(g) → 12CO₂(g) + 11H₂O(l)
✔ *Type:* Combustion / Biological Oxidation
---
## ✔ Final Notes:
- Formation: Element + Element → Compound
- Decomposition: Compound → Elements or simpler compounds
- Single Replacement: A + BC → AC + B
- Double Replacement: AB + CD → AD + CB
- Combustion: Hydrocarbon + O₂ → CO₂ + H₂O
- Other: Redox, complex reactions not fitting above
All equations are now balanced with correct stoichiometry and reaction types identified.
Let me know if you’d like a printable version or step-by-step balancing for any specific equation!
---
## Part 1: Balance the following equations and indicate the type of reaction
a.
Unbalanced: Cu(s) + O₂(g) → CuO(s)
Balanced: 2Cu(s) + O₂(g) → 2CuO(s)
✔ *Type:* Formation (two elements combine to form one compound)
---
b.
Unbalanced: H₂O(l) → H₂(g) + O₂(g)
Balanced: 2H₂O(l) → 2H₂(g) + O₂(g)
✔ *Type:* Decomposition (one compound breaks into two elements)
---
c.
Unbalanced: Fe(s) + H₂O(g) → H₂(g) + Fe₃O₄(s)
Balanced: 3Fe(s) + 4H₂O(g) → 4H₂(g) + Fe₃O₄(s)
✔ *Type:* Single Replacement (Fe displaces H from H₂O)
---
d.
Unbalanced: AsCl₃(aq) + H₂S(aq) → As₂S₃(s) + HCl(aq)
Balanced: 2AsCl₃(aq) + 3H₂S(aq) → As₂S₃(s) + 6HCl(aq)
✔ *Type:* Double Replacement (ions swap partners; precipitate forms)
---
e.
Unbalanced: CuSO₄·5H₂O(s) → CuSO₄(s) + H₂O(g)
Balanced: CuSO₄·5H₂O(s) → CuSO₄(s) + 5H₂O(g)
✔ *Type:* Decomposition (hydrated salt loses water molecules)
---
f.
Unbalanced: Fe₂O₃(s) + H₂(g) → Fe(s) + H₂O(l)
Balanced: Fe₂O₃(s) + 3H₂(g) → 2Fe(s) + 3H₂O(l)
✔ *Type:* Single Replacement (H₂ reduces Fe₂O₃ to Fe)
---
g.
Unbalanced: CaCO₃(s) → CaO(s) + CO₂(g)
Balanced: CaCO₃(s) → CaO(s) + CO₂(g)
✔ *Type:* Decomposition (carbonate decomposes to oxide + CO₂)
---
h.
Unbalanced: Fe(s) + S₈(s) → FeS(s)
Balanced: 8Fe(s) + S₈(s) → 8FeS(s)
✔ *Type:* Formation (elements combine to form a compound)
---
i.
Unbalanced: H₂S(aq) + KOH(aq) → H₂O(l) + K₂S(aq)
Balanced: H₂S(aq) + 2KOH(aq) → 2H₂O(l) + K₂S(aq)
✔ *Type:* Double Replacement / Acid-Base Neutralization
---
j.
Unbalanced: NaCl(l) → Na(l) + Cl₂(g)
Balanced: 2NaCl(l) → 2Na(l) + Cl₂(g)
✔ *Type:* Decomposition (electrolysis of molten salt)
---
k.
Unbalanced: Al(s) + H₂SO₄(aq) → H₂(g) + Al₂(SO₄)₃(aq)
Balanced: 2Al(s) + 3H₂SO₄(aq) → 3H₂(g) + Al₂(SO₄)₃(aq)
✔ *Type:* Single Replacement (Al displaces H from acid)
---
l.
Unbalanced: H₃PO₄(aq) + NH₄OH(aq) → H₂O(l) + (NH₄)₃PO₄(aq)
Balanced: H₃PO₄(aq) + 3NH₄OH(aq) → 3H₂O(l) + (NH₄)₃PO₄(aq)
✔ *Type:* Double Replacement / Acid-Base Neutralization
---
m.
Unbalanced: C₃H₈(g) + O₂(g) → CO₂(g) + H₂O(l)
Balanced: C₃H₈(g) + 5O₂(g) → 3CO₂(g) + 4H₂O(l)
✔ *Type:* Hydrocarbon Combustion
---
n.
Unbalanced: Al(s) + O₂(g) → Al₂O₃(s)
Balanced: 4Al(s) + 3O₂(g) → 2Al₂O₃(s)
✔ *Type:* Formation
---
o.
Unbalanced: CH₄(g) + O₂(g) → CO₂(g) + H₂O(l)
Balanced: CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(l)
✔ *Type:* Hydrocarbon Combustion
---
p.
Unbalanced: K₂SO₄(aq) + BaCl₂(aq) → KCl(aq) + BaSO₄(s)
Balanced: K₂SO₄(aq) + BaCl₂(aq) → 2KCl(aq) + BaSO₄(s)
✔ *Type:* Double Replacement (precipitation reaction)
---
q.
Unbalanced: C₅H₁₂(l) + O₂(g) → CO₂(g) + H₂O(g)
Balanced: C₅H₁₂(l) + 8O₂(g) → 5CO₂(g) + 6H₂O(g)
✔ *Type:* Hydrocarbon Combustion
---
r.
Unbalanced: Ca(OH)₂(aq) + NH₄Cl(aq) → NH₄OH(aq) + CaCl₂(aq)
Balanced: Ca(OH)₂(aq) + 2NH₄Cl(aq) → 2NH₄OH(aq) + CaCl₂(aq)
✔ *Type:* Double Replacement
> Note: In reality, NH₄OH decomposes to NH₃(g) + H₂O(l), but as written, we balance as is.
---
s.
Unbalanced: V₂O₅(s) + Ca(s) → CaO(s) + V(s)
Balanced: V₂O₅(s) + 5Ca(s) → 5CaO(s) + 2V(s)
✔ *Type:* Single Replacement (Ca reduces vanadium oxide)
---
t.
Unbalanced: Na(s) + ZnI₂(aq) → NaI(aq) + Zn(s)
Balanced: 2Na(s) + ZnI₂(aq) → 2NaI(aq) + Zn(s)
✔ *Type:* Single Replacement (Na displaces Zn)
---
u.
Unbalanced: C₇H₆O₃(l) + O₂(g) → CO₂(g) + H₂O(l)
*(This is salicylic acid — C₇H₆O₃)*
Balanced: C₇H₆O₃(l) + 7O₂(g) → 7CO₂(g) + 3H₂O(l)
✔ *Type:* Combustion (organic compound burns in oxygen)
---
v.
Unbalanced: Ca(s) + N₂(g) → Ca₃N₂(s)
Balanced: 3Ca(s) + N₂(g) → Ca₃N₂(s)
✔ *Type:* Formation
---
w.
Unbalanced: Fe₂O₃(s) + H₂(g) → Fe(s) + H₂O(l)
Balanced: Fe₂O₃(s) + 3H₂(g) → 2Fe(s) + 3H₂O(l)
✔ *Type:* Single Replacement (same as f — reduction by H₂)
---
x.
Unbalanced: C₁₅H₃₀(l) + O₂(g) → CO₂(g) + H₂O(g)
Balanced: 2C₁₅H₃₀(l) + 45O₂(g) → 30CO₂(g) + 30H₂O(g)
✔ *Type:* Hydrocarbon Combustion
---
y.
Unbalanced: BN(s) + F₂(g) → BF₃(s) + N₂(g)
Balanced: 2BN(s) + 3F₂(g) → 2BF₃(s) + N₂(g)
✔ *Type:* Single Replacement (F displaces N? Actually, it’s a redox reaction — can classify as “Other” or “Combination/Redox”)
> Since B and N are covalently bonded, and F₂ oxidizes both, this is best called “Other” (redox).
---
z.
Unbalanced: C₁₂H₂₆(l) + O₂(g) → CO₂(g) + H₂O(g)
Balanced: 2C₁₂H₂₆(l) + 37O₂(g) → 24CO₂(g) + 26H₂O(g)
✔ *Type:* Hydrocarbon Combustion
---
## Part 2: Predict products, states, type, and balance
---
a. Lead(II) nitrate + sodium iodide
Reaction: Pb(NO₃)₂(aq) + 2NaI(aq) → PbI₂(s) + 2NaNO₃(aq)
✔ *Type:* Double Replacement / Precipitation
*Note:* PbI₂ is a bright yellow precipitate.
---
b. Zinc sulfide + oxygen
Reaction: 2ZnS(s) + 3O₂(g) → 2ZnO(s) + 2SO₂(g)
✔ *Type:* Combustion / Redox
*Note:* Metal sulfide reacts with O₂ to form metal oxide and SO₂.
---
c. Butane (C₄H₁₀) ignites
Reaction: 2C₄H₁₀(l) + 13O₂(g) → 8CO₂(g) + 10H₂O(g)
✔ *Type:* Hydrocarbon Combustion
---
d. Barium hydroxide + HCl
Reaction: Ba(OH)₂(aq) + 2HCl(aq) → BaCl₂(aq) + 2H₂O(l)
✔ *Type:* Double Replacement / Acid-Base Neutralization
---
e. Copper metal + silver nitrate
Reaction: Cu(s) + 2AgNO₃(aq) → Cu(NO₃)₂(aq) + 2Ag(s)
✔ *Type:* Single Replacement
*Note:* Cu displaces Ag⁺ because Cu is more reactive than Ag.
---
f. Sulfur + oxygen → sulfur dioxide
Reaction: S(s) + O₂(g) → SO₂(g)
✔ *Type:* Formation / Combustion
---
g. Aluminum sulfate + calcium hydroxide
Reaction: Al₂(SO₄)₃(aq) + 3Ca(OH)₂(aq) → 2Al(OH)₃(s) + 3CaSO₄(s)
✔ *Type:* Double Replacement / Precipitation
*Note:* Both Al(OH)₃ and CaSO₄ may precipitate (CaSO₄ is slightly soluble).
---
h. Zinc metal + sulfuric acid
Reaction: Zn(s) + H₂SO₄(aq) → ZnSO₄(aq) + H₂(g)
✔ *Type:* Single Replacement
---
i. Aluminum powder + chlorine gas
Reaction: 2Al(s) + 3Cl₂(g) → 2AlCl₃(s)
✔ *Type:* Formation
---
j. Sucrose undergoes cellular respiration
Reaction: C₁₂H₂₂O₁₁(s) + 12O₂(g) → 12CO₂(g) + 11H₂O(l)
✔ *Type:* Combustion / Biological Oxidation
---
## ✔ Final Notes:
- Formation: Element + Element → Compound
- Decomposition: Compound → Elements or simpler compounds
- Single Replacement: A + BC → AC + B
- Double Replacement: AB + CD → AD + CB
- Combustion: Hydrocarbon + O₂ → CO₂ + H₂O
- Other: Redox, complex reactions not fitting above
All equations are now balanced with correct stoichiometry and reaction types identified.
Let me know if you’d like a printable version or step-by-step balancing for any specific equation!
Parent Tip: Review the logic above to help your child master the concept of chemical equations and reactions worksheet answers.
![49 Balancing Chemical Equations Worksheets [with Answers]](/images2/chemical-equations-and-reactions-worksheet-answers/chemical-equations-and-reactions-worksheet-answers-18.jpg)
