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 start with #1:

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

Na and K are unbalanced. Try putting 3 in front of NaOH and 3 in front of KOH:

→ 1 Na₃PO₄ + 3 KOH → 3 NaOH + 1 K₃PO₄

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 ✔ Balanced!

So: 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

Li and F are half on right. Put 2 in front of LiF:

→ 1 MgF₂ + 1 Li₂CO₃ → 1 MgCO₃ + 2 LiF

Check:
Left: Mg=1, F=2, Li=2, C=1, O=3
Right: Mg=1, C=1, O=3, Li=2, F=2 ✔

Answer: 1, 1, 1, 2

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3) P₄ + O₂ → P₂O₃

Left: P=4, O=2
Right: P=2, O=3

Need to get even numbers. Let’s try 2 P₂O₃ → that gives P=4, O=6

So need 3 O₂ (since 3×2=6 oxygen atoms)

→ 1 P₄ + 3 O₂ → 2 P₂O₃

Check: P=4, O=6 on both sides ✔

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

N and O doubled on right → need 2 RbNO₃
Then Rb becomes 2 → need 2 RbF
F was 2 on left, now 2 on right → good

→ 2 RbNO₃ + 1 BeF₂ → 1 Be(NO₃)₂ + 2 RbF

Check:
Left: Rb=2, N=2, O=6, Be=1, F=2
Right: Be=1, N=2, O=6, Rb=2, F=2 ✔

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 to match nitrate → then Ag=2 → need 2 Ag on right

→ 2 AgNO₃ + 1 Cu → 1 Cu(NO₃)₂ + 2 Ag

Check: Ag=2, N=2, O=6, Cu=1 ✔

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

Br needs to be 4 → so 2 Br₂
F needs to be 4 → so 2 F₂

→ 1 CF₄ + 2 Br₂ → 1 CBr₄ + 2 F₂

Check: C=1, F=4, Br=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 to get C=2, N=2 → then H=2 → matches H₂SO₄

→ 2 HCN + 1 CuSO₄ → 1 H₂SO₄ + 1 Cu(CN)₂

Check: H=2, C=2, N=2, Cu=1, S=1, O=4 ✔

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

F is 3 on left, 1 on right → need 3 CsF → then Cs=3 → need 3 Cs on left

→ 1 GaF₃ + 3 Cs → 3 CsF + 1 Ga

Check: Ga=1, F=3, Cs=3 ✔

Answer: 1, 3, 3, 1

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9) BaS + PtF₂ → BaF₂ + PtS

Already balanced? Check:

Left: Ba=1, S=1, Pt=1, F=2
Right: Ba=1, F=2, Pt=1, S=1 ✔

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 → N=2, H=6 → so need 3 H₂

→ 1 N₂ + 3 H₂ → 2 NH₃

Check: N=2, 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

F is 1 vs 2 → need 2 NaF → then Na=2 → need 2 NaBr
Br was 2 on left, now 2 on right → good

→ 2 NaF + 1 Br₂ → 2 NaBr + 1 F₂

Check: Na=2, F=2, Br=2 ✔

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

Cl is 1 vs 2 → need 2 HCl → then H=2+2=4, Cl=2
On right, H₂O has H=2 → need 2 H₂O to get H=4, O=2

→ 1 Pb(OH)₂ + 2 HCl → 2 H₂O + 1 PbCl₂

Check: Pb=1, O=2, H=4, Cl=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

Al: 1 vs 2 → need 2 AlBr₃
Br: 6 → need 6 KBr
K: 6 → need 3 K₂SO₄
S: 3 → matches Al₂(SO₄)₃
O: 12 → matches

→ 2 AlBr₃ + 3 K₂SO₄ → 6 KBr + 1 Al₂(SO₄)₃

Check: Al=2, Br=6, K=6, S=3, O=12 ✔

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, H=2

H: 4 vs 2 → need 2 H₂O → H=4, O=2 from water + 2 from CO₂ = 4 total O → need 2 O₂

→ 1 CH₄ + 2 O₂ → 1 CO₂ + 2 H₂O

Check: C=1, H=4, 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

P: 1 vs 2 → need 2 Na₃PO₄ → Na=6, P=2, O=8
Ca: 3 → need 3 CaCl₂ → Cl=6
NaCl: need 6 to match Na=6 and Cl=6

→ 2 Na₃PO₄ + 3 CaCl₂ → 6 NaCl + 1 Ca₃(PO₄)₂

Check: Na=6, P=2, O=8, Ca=3, 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 → then K=2 → need 2 K

→ 2 K + 1 Cl₂ → 2 KCl

Check: K=2, Cl=2 ✔

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

Cl: 1 vs 3 → need 3 HCl → H=3 → but H₂ needs even → so double everything

Try 2 Al + 6 HCl → 3 H₂ + 2 AlCl₃

Check: Al=2, H=6, Cl=6 → Right: H=6, Al=2, Cl=6 ✔

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 → so 3 F₂

→ 1 N₂ + 3 F₂ → 2 NF₃

Check: N=2, 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

Se: 1 vs 2 → need 2 Li₂Se → Li=4, Se=2
O: 2 vs 1 → need 2 Li₂O → Li=4, O=2
SSe₂ already has S=1, Se=2 → good

→ 1 SO₂ + 2 Li₂Se → 1 SSe₂ + 2 Li₂O

Check: S=1, O=2, Li=4, Se=2 ✔

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

N: 1 vs 2 → need 2 NH₃ → H=6 from ammonia + 2 from acid = 8 → perfect

→ 2 NH₃ + 1 H₂SO₄ → 1 (NH₄)₂SO₄

Check: N=2, H=8, S=1, O=4 ✔

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