49 Balancing Chemical Equations Worksheets [with Answers] - Free Printable

Let’s go through each equation one by one and balance them. Balancing means making sure the number of atoms of each element is the same on both sides of the arrow.

We’ll write the coefficients (the numbers in front) that make each equation balanced.

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1) Na₃PO₄ + KOH → NaOH + K₃PO₄
Left: Na=3, P=1, O=4+1=5, K=1, H=1
Right: Na=1, O=1+4=5, H=1, K=3, P=1
→ Need 3 NaOH to match Na from left → now Na=3, but K=3 on right, so need 3 KOH on left
Check:
Left: Na=3, P=1, O=4+3=7, K=3, H=3
Right: Na=3, O=3+4=7, H=3, K=3, P=1 ✔
Answer: 1, 3, 3, 1

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2) MgF₂ + Li₂CO₃ → MgCO₃ + LiF
Left: Mg=1, F=2, Li=2, C=1, O=3
Right: Mg=1, C=1, O=3, Li=1, F=1
→ Need 2 LiF on right to match Li and F
Answer: 1, 1, 1, 2

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3) P₄ + O₂ → P₂O₃
Left: P=4, O=?
Right: P=2, O=3
→ To get 4 P on right, need 2 P₂O₃ → now P=4, O=6
→ So need 3 O₂ on left (since 3×2=6 O)
Answer: 1, 3, 2

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4) RbNO₃ + BeF₂ → Be(NO₃)₂ + RbF
Left: Rb=1, N=1, O=3, Be=1, F=2
Right: Be=1, N=2, O=6, Rb=1, F=1
→ Need 2 RbNO₃ on left → now Rb=2, N=2, O=6
→ Then need 2 RbF on right to match Rb and F (BeF₂ gives 2 F, so 2 RbF uses 2 F)
Answer: 2, 1, 1, 2

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5) AgNO₃ + Cu → Cu(NO₃)₂ + Ag
Left: Ag=1, N=1, O=3, Cu=1
Right: Cu=1, N=2, O=6, Ag=1
→ Need 2 AgNO₃ on left → now Ag=2, N=2, O=6
→ Then need 2 Ag on right
Answer: 2, 1, 1, 2

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6) CF₄ + Br₂ → CBr₄ + F₂
Left: C=1, F=4, Br=2
Right: C=1, Br=4, F=2
→ Need 2 Br₂ on left → Br=4
→ Need 2 F₂ on right → F=4
Answer: 1, 2, 1, 2

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7) HCN + CuSO₄ → H₂SO₄ + Cu(CN)₂
Left: H=1, C=1, N=1, Cu=1, S=1, O=4
Right: H=2, S=1, O=4, Cu=1, C=2, N=2
→ Need 2 HCN on left → H=2, C=2, N=2
→ Now matches right side
Answer: 2, 1, 1, 1

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8) GaF₃ + Cs → CsF + Ga
Left: Ga=1, F=3, Cs=1
Right: Cs=1, F=1, Ga=1
→ Need 3 CsF on right → then need 3 Cs on left
Answer: 1, 3, 3, 1

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9) BaS + PtF₂ → BaF₂ + PtS
Left: Ba=1, S=1, Pt=1, F=2
Right: Ba=1, F=2, Pt=1, S=1
Already balanced!
Answer: 1, 1, 1, 1

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10) N₂ + H₂ → NH₃
Left: N=2, H=2
Right: N=1, H=3
→ Need 2 NH₃ on right → N=2, H=6
→ Then need 3 H₂ on left → H=6
Answer: 1, 3, 2

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11) NaF + Br₂ → NaBr + F₂
Left: Na=1, F=1, Br=2
Right: Na=1, Br=1, F=2
→ Need 2 NaF on left → Na=2, F=2
→ Then need 2 NaBr on right → Na=2, Br=2
→ Br₂ already gives 2 Br
Answer: 2, 1, 2, 1

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12) Pb(OH)₂ + HCl → H₂O + PbCl₂
Left: Pb=1, O=2, H=2+1=3, Cl=1
Right: H=2, O=1, Pb=1, Cl=2
→ Need 2 HCl on left → Cl=2, H=2 more → total H=4, O=2
→ Need 2 H₂O on right → H=4, O=2
Answer: 1, 2, 2, 1

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13) AlBr₃ + K₂SO₄ → KBr + Al₂(SO₄)₃
Left: Al=1, Br=3, K=2, S=1, O=4
Right: K=1, Br=1, Al=2, S=3, O=12
→ Need 2 AlBr₃ → Al=2, Br=6
→ Need 3 K₂SO₄ → K=6, S=3, O=12
→ Then need 6 KBr on right → K=6, Br=6
Answer: 2, 3, 6, 1

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14) CH₄ + O₂ → CO₂ + H₂O
Left: C=1, H=4, O=2
Right: C=1, O=2+1=3? Wait — CO₂ has 2 O, H₂O has 1 O per molecule
→ Need 2 H₂O to get H=4 → then O from products: 2 (from CO₂) + 2 (from 2 H₂O) = 4 O
→ So need 2 O₂ on left → O=4
Answer: 1, 2, 1, 2

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15) Na₃PO₄ + CaCl₂ → NaCl + Ca₃(PO₄)₂
Left: Na=3, P=1, O=4, Ca=1, Cl=2
Right: Na=1, Cl=1, Ca=3, P=2, O=8
→ Need 2 Na₃PO₄ → Na=6, P=2, O=8
→ Need 3 CaCl₂ → Ca=3, Cl=6
→ Then need 6 NaCl on right → Na=6, Cl=6
Answer: 2, 3, 6, 1

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16) K + Cl₂ → KCl
Left: K=1, Cl=2
Right: K=1, Cl=1
→ Need 2 KCl on right → then need 2 K on left
Answer: 2, 1, 2

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17) Al + HCl → H₂ + AlCl₃
Left: Al=1, H=1, Cl=1
Right: H=2, Al=1, Cl=3
→ Need 3 HCl on left → H=3, Cl=3 → but H₂ needs even H
→ Try 2 Al → then need 2 AlCl₃ → Cl=6 → so 6 HCl → H=6 → makes 3 H₂
Answer: 2, 6, 3, 2

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18) N₂ + F₂ → NF₃
Left: N=2, F=2
Right: N=1, F=3
→ Need 2 NF₃ → N=2, F=6
→ Need 3 F₂ → F=6
Answer: 1, 3, 2

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19) SO₂ + Li₂Se → SSe₂ + Li₂O
Left: S=1, O=2, Li=2, Se=1
Right: S=1, Se=2, Li=2, O=1
→ Need 2 Li₂O on right → O=2, Li=4 → so need 2 Li₂Se on left → Li=4, Se=2
→ Then SSe₂ already has S=1, Se=2
→ SO₂ has S=1, O=2
Perfect
Answer: 1, 2, 1, 2

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20) NH₃ + H₂SO₄ → (NH₄)₂SO₄
Left: N=1, H=3+2=5, S=1, O=4
Right: N=2, H=8, S=1, O=4
→ Need 2 NH₃ → N=2, H=6 → plus H₂SO₄ adds 2 H → total H=8
Matches right side
Answer: 2, 1, 1

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Final Answer:
1) 1, 3, 3, 1
2) 1, 1, 1, 2
3) 1, 3, 2
4) 2, 1, 1, 2
5) 2, 1, 1, 2
6) 1, 2, 1, 2
7) 2, 1, 1, 1
8) 1, 3, 3, 1
9) 1, 1, 1, 1
10) 1, 3, 2
11) 2, 1, 2, 1
12) 1, 2, 2, 1
13) 2, 3, 6, 1
14) 1, 2, 1, 2
15) 2, 3, 6, 1
16) 2, 1, 2
17) 2, 6, 3, 2
18) 1, 3, 2
19) 1, 2, 1, 2
20) 2, 1, 1