Worksheet for practicing writing and balancing chemical equations by converting word equations to chemical formulas.

Let’s go through each problem one by one. We’ll write the correct chemical formulas first, then balance the equations so that the number of atoms of each element is the same on both sides.

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1. sodium chloride + lead (II) nitrate → lead (II) chloride + sodium nitrate

- Sodium chloride = NaCl
- Lead(II) nitrate = Pb(NO₃)₂
- Lead(II) chloride = PbCl₂
- Sodium nitrate = NaNO₃

Unbalanced:
NaCl + Pb(NO₃)₂ → PbCl₂ + NaNO₃

Balance:
We need 2 Na and 2 NO₃ on the right → put 2 in front of NaCl and 2 in front of NaNO₃.

✔ Balanced:
2NaCl + Pb(NO₃)₂ → PbCl₂ + 2NaNO₃

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2. barium + water → barium hydroxide + hydrogen

- Barium = Ba
- Water = H₂O
- Barium hydroxide = Ba(OH)₂
- Hydrogen = H₂

Unbalanced:
Ba + H₂O → Ba(OH)₂ + H₂

Balance:
Left has 2 H, right has 4 H (2 from OH and 2 from H₂). So we need 2 H₂O on left.

Try:
Ba + 2H₂O → Ba(OH)₂ + H₂

Check atoms:
Ba: 1=1
H: 4 = 2 (in OH) + 2 (in H₂) → 4=4 ✔
O: 2 = 2 ✔

✔ Balanced:
Ba + 2H₂O → Ba(OH)₂ + H₂

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3. copper (II) carbonate → copper (II) oxide + carbon dioxide

- Copper(II) carbonate = CuCO₃
- Copper(II) oxide = CuO
- Carbon dioxide = CO₂

Unbalanced:
CuCO₃ → CuO + CO₂

Already balanced! Each side has 1 Cu, 1 C, 3 O.

✔ Balanced:
CuCO₃ → CuO + CO₂

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4. hydrobromic acid + potassium hydroxide → potassium bromide + water

- Hydrobromic acid = HBr
- Potassium hydroxide = KOH
- Potassium bromide = KBr
- Water = H₂O

Unbalanced:
HBr + KOH → KBr + H₂O

Already balanced! All elements match.

✔ Balanced:
HBr + KOH → KBr + H₂O

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5. zinc + lead (II) nitrate → zinc nitrate + lead

- Zinc = Zn
- Lead(II) nitrate = Pb(NO₃)₂
- Zinc nitrate = Zn(NO₃)₂
- Lead = Pb

Unbalanced:
Zn + Pb(NO₃)₂ → Zn(NO₃)₂ + Pb

Already balanced! One of each atom/ion group.

✔ Balanced:
Zn + Pb(NO₃)₂ → Zn(NO₃)₂ + Pb

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6. sodium phosphate + calcium chloride → calcium phosphate + sodium chloride

- Sodium phosphate = Na₃PO₄
- Calcium chloride = CaCl₂
- Calcium phosphate = Ca₃(PO₄)₂
- Sodium chloride = NaCl

Unbalanced:
Na₃PO₄ + CaCl₂ → Ca₃(PO₄)₂ + NaCl

Balance step-by-step:

Right has 3 Ca → need 3 CaCl₂ on left
Right has 2 PO₄ → need 2 Na₃PO₄ on left
Now left has 6 Na → need 6 NaCl on right

So:
2Na₃PO₄ + 3CaCl₂ → Ca₃(PO)₂ + 6NaCl

Check:
Na: 6 = 6
P: 2 = 2
O: 8 = 8
Ca: 3 = 3
Cl: 6 = 6 ✔

✔ Balanced:
2Na₃PO₄ + 3CaCl₂ → Ca₃(PO₄)₂ + 6NaCl

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7. iron (III) chloride + sodium hydroxide → iron (III) hydroxide + sodium chloride

- Iron(III) chloride = FeCl₃
- Sodium hydroxide = NaOH
- Iron(III) hydroxide = Fe(OH)₃
- Sodium chloride = NaCl

Unbalanced:
FeCl₃ + NaOH → Fe(OH)₃ + NaCl

Balance:
Fe: 1=1
Cl: 3 → need 3 NaCl
OH: 3 → need 3 NaOH

So:
FeCl₃ + 3NaOH → Fe(OH)₃ + 3NaCl

Check:
Fe:1=1, Cl:3=3, Na:3=3, O:3=3, H:3=3 ✔

✔ Balanced:
FeCl₃ + 3NaOH → Fe(OH)₃ + 3NaCl

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8. hydrochloric acid + calcium carbonate → calcium chloride + water + carbon dioxide

- Hydrochloric acid = HCl
- Calcium carbonate = CaCO₃
- Calcium chloride = CaCl₂
- Water = H₂O
- Carbon dioxide = CO₂

Unbalanced:
HCl + CaCO₃ → CaCl₂ + H₂O + CO₂

Balance:
Ca: 1=1
C: 1=1
O: 3 = 1 (H₂O) + 2 (CO₂) → 3=3 ✔
But Cl: left=1, right=2 → need 2 HCl
Then H: left=2, right=2 (in H₂O) ✔

So:
2HCl + CaCO₃ → CaCl₂ + H₂O + CO₂

✔ Balanced:
2HCl + CaCO₃ → CaCl₂ + H₂O + CO₂

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9. silver (I) oxide → silver + oxygen

- Silver(I) oxide = Ag₂O
- Silver = Ag
- Oxygen = O₂

Unbalanced:
Ag₂O → Ag + O₂

Balance:
Left: 2 Ag, 1 O
Right: 1 Ag, 2 O → not balanced

Need to make O even on left → try 2Ag₂O → gives 4 Ag and 2 O

Then right: 4 Ag and 1 O₂ → perfect!

So:
2Ag₂O → 4Ag + O₂

✔ Balanced:
2Ag₂O → 4Ag + O₂

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10. sodium oxide + water → sodium hydroxide

- Sodium oxide = Na₂O
- Water = H₂O
- Sodium hydroxide = NaOH

Unbalanced:
Na₂O + H₂O → NaOH

Left: 2 Na, 2 H, 2 O
Right: 1 Na, 1 H, 1 O → need 2 NaOH

So:
Na₂O + H₂O → 2NaOH

Check:
Na:2=2, H:2=2, O:2=2 ✔

✔ Balanced:
Na₂O + H₂O → 2NaOH

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Final Answer:
1. 2NaCl + Pb(NO₃)₂ → PbCl₂ + 2NaNO₃
2. Ba + 2H₂O → Ba(OH)₂ + H₂
3. CuCO₃ → CuO + CO₂
4. HBr + KOH → KBr + H₂O
5. Zn + Pb(NO₃)₂ → Zn(NO₃)₂ + Pb
6. 2Na₃PO₄ + 3CaCl₂ → Ca₃(PO₄)₂ + 6NaCl
7. FeCl₃ + 3NaOH → Fe(OH)₃ + 3NaCl
8. 2HCl + CaCO₃ → CaCl₂ + H₂O + CO₂
9. 2Ag₂O → 4Ag + O₂
10. Na₂O + H₂O → 2NaOH