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

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

We’ll start with #1 and work our way down to #20. I’ll write the balanced coefficients in order for each reaction.

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1) Li₃PO₄ + NaOH → LiOH + Na₃PO₄

Left: Li=3, P=1, O=4+1=5, Na=1, H=1
Right: Li=1, O=1+4=5, H=1, Na=3, P=1

To balance Na: put 3 in front of NaOH → now Na=3 left
Then Li: left has 3, right has 1 → put 3 in front of LiOH
Now check:
Left: Li=3, P=1, O=4+3=7, Na=3, H=3
Right: Li=3, O=3+4=7, H=3, Na=3, P=1 → Balanced!

✔ 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 → Li=2, F=2
Everything else already matches.

✔ 1, 1, 1, 2

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3) P₄ + O₂ → P₂O₃

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

Make P equal: put 2 in front of P₂O₃ → P=4, O=6
Now O: need 3 O₂ on left → O=6

✔ 1, 3, 2

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4) RbNO₃ + MgF₂ → Mg(NO₃)₂ + RbF

Left: Rb=1, N=1, O=3, Mg=1, F=2
Right: Mg=1, N=2, O=6, Rb=1, F=1

Need 2 RbNO₃ on left → Rb=2, N=2, O=6
Then need 2 RbF on right → Rb=2, F=2
MgF₂ already gives F=2 → good

✔ 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 → Ag=2, N=2, O=6
Then need 2 Ag on right

✔ 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

✔ 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
Everything else matches.

✔ 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 → Cs=3, F=3
So need 3 Cs on left

✔ 1, 3, 3, 1

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9) SrS + PtF₂ → SrF₂ + PtS

All elements match as written.

✔ 1, 1, 1, 1

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10) N₂ + H₂ → NH₃

Left: N=2, H=2
Right: N=1, H=3

Put 2 in front of NH₃ → N=2, H=6
Then need 3 H₂ on left → H=6

✔ 1, 3, 2

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11) LiF + Br₂ → LiBr + F₂

Left: Li=1, F=1, Br=2
Right: Li=1, Br=1, F=2

Need 2 LiF on left → Li=2, F=2
Need 2 LiBr on right → Li=2, Br=2
Br₂ already gives Br=2 → good

✔ 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 → H=2+2=4, Cl=2
Then need 2 H₂O on right → H=4, O=2

✔ 1, 2, 2, 1

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13) GaBr₃ + Na₂CO₃ → NaBr + Ga₂(CO₃)₃ (tough)

Left: Ga=1, Br=3, Na=2, C=1, O=3
Right: Na=1, Br=1, Ga=2, C=3, O=9

Start with Ga: need 2 GaBr₃ → Ga=2, Br=6
Then NaBr: need 6 → Na=6, Br=6
Na₂CO₃: need 3 → Na=6, C=3, O=9
Ga₂(CO₃)₃: already has Ga=2, C=3, O=9 → perfect

✔ 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

Need 2 H₂O → H=4, O=2+2=4? Wait: CO₂ has 2 O, 2 H₂O has 2 O → total 4 O
So need 2 O₂ on left → O=4

✔ 1, 2, 1, 2

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15) Li₃PO₄ + CaCl₂ → LiCl + Ca₃(PO)₂ (also tough)

Left: Li=3, P=1, O=4, Ca=1, Cl=2
Right: Li=1, Cl=1, Ca=3, P=2, O=8

Start with Ca: need 3 CaCl₂ → Ca=3, Cl=6
Then LiCl: need 6 → Li=6, Cl=6
Li₃PO₄: need 2 → Li=6, P=2, O=8
Ca₃(PO)₂: already has Ca=3, P=2, O=8 → good

✔ 2, 3, 6, 1

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16) Na + Cl₂ → NaCl

Left: Na=1, Cl=2
Right: Na=1, Cl=1

Need 2 NaCl → Na=2, Cl=2
So need 2 Na on left

✔ 2, 1, 2

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17) Ga + HCl → H₂ + GaCl₃ (last tough one)

Left: Ga=1, H=1, Cl=1
Right: H=2, Ga=1, Cl=3

Need 3 HCl → H=3, Cl=3
But H₂ needs even H → so double everything:

Try 2 Ga + 6 HCl → 3 H₂ + 2 GaCl₃
Check:
Left: Ga=2, H=6, Cl=6
Right: H=6, Ga=2, Cl=6 → good

✔ 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
Then need 3 F₂ → F=6

✔ 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 → O=2, Li=4
Then need 2 Li₂Se → Li=4, Se=2
SSe₂ already has Se=2 → good

Wait — let's recheck:

If we do:
SO₂ + 2 Li₂Se → SSe₂ + 2 Li₂O
Left: S=1, O=2, Li=4, Se=2
Right: S=1, Se=2, Li=4, O=2 → yes!

✔ 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 → H=2 → total H=8 → perfect

✔ 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