Worksheet for practicing writing balanced chemical equations.

I'll work through each chemical equation step by step, balancing them carefully.

a) aluminum bromide + chlorine → aluminum chloride + bromine
- Aluminum bromide: AlBr₃
- Chlorine: Cl₂
- Aluminum chloride: AlCl₃
- Bromine: Br₂

Unbalanced: AlBr₃ + Cl₂ → AlCl₃ + Br₂

Let me balance this:
- Start with 2AlBr₃ to get even number of Br atoms
- 2AlBr₃ + 3Cl₂ → 2AlCl₃ + 3Br₂

Check: Al: 2=2 ✓, Br: 6=6 ✓, Cl: 6=6 ✓

b) calcium sulfite → calcium oxide + sulfur dioxide
- Calcium sulfite: CaSO₃
- Calcium oxide: CaO
- Sulfur dioxide: SO₂

Unbalanced: CaSO₃ → CaO + SO₂

Check: Ca: 1=1 ✓, S: 1=1 ✓, O: 3=1+2=3 ✓

Already balanced!

c) phosphoric acid + calcium hydroxide → calcium phosphate + water
- Phosphoric acid: H₃PO₄
- Calcium hydroxide: Ca(OH)₂
- Calcium phosphate: Ca₃(PO₄)₂
- Water: H₂O

Unbalanced: H₃PO₄ + Ca(OH)₂ → Ca₃(PO₄)₂ + H₂O

Need 2 PO₄ groups on left, so 2H₃PO₄
Need 3 Ca on right, so 3Ca(OH)₂

2H₃PO + 3Ca(OH)₂ → Ca(PO₄)₂ + H₂O

Now check H: left has 2×3 + 3×2 = 6 + 6 = 12 H
Right needs 6H₂O for 12 H

2H₃PO₄ + 3Ca(OH)₂ → Ca₃(PO₄)₂ + 6H₂O

Check: H: 12=12 ✓, P: 2=2 ✓, O: 8+6=14 and 8+6=14 ✓, Ca: 3=3 ✓

d) silver nitrate + ammonium carbonate → silver carbonate + ammonium nitrate
- Silver nitrate: AgNO₃
- Ammonium carbonate: (NH₄)₂CO₃
- Silver carbonate: Ag₂CO₃
- Ammonium nitrate: NH₄NO₃

Unbalanced: AgNO₃ + (NH)₂CO₃ → Ag₂CO₃ + NH₄NO₃

Need 2Ag on left: 2AgNO₃
Need 2NH₄NO₃ on right for the 2 NH₄ groups

2AgNO₃ + (NH₄)₂CO₃ → Ag₂CO₃ + 2NH₄NO₃

Check: Ag: 2=2 ✓, N: 2+2=4 and 2 ✓... wait, let me recount
Left: 2N from AgNO₃ + 2N from (NH₄)₂CO₃ = 4N total
Right: 2N from 2NH₄NO₃ = 2N... that's wrong

Let me reconsider: (NH₄)₂CO₃ has 2 NH₄ groups, each NH₄NO₃ has 1 NH₄ group
So we need 2NH₄NO₃

But nitrogen count: Left has 2 (from 2AgNO) + 2 (from (NH₄)₂CO₃) = 4
Right has 2 (from 2NH₄NO₃)... still doesn't match

Actually, I need to think about this differently. Each NHNO₃ contains one N from NH and one N from NO₃.
So 2NH₄NO₃ has 4N total (2 from NH₄ and 2 from NO₃).

Let me verify: 2AgNO₃ + (NH₄)₂CO₃ → Ag₂CO₃ + 2NH₄NO₃
Ag: 2=2 ✓
N: 2+2=4 and 2×2=4 ✓
O: 6+3=9 and 3+6=9 ✓
NH₄: 2=2 ✓
C: 1=1 ✓

e) lithium hydrogen carbonate → lithium carbonate + water + carbon dioxide
- Lithium hydrogen carbonate: LiHCO₃
- Lithium carbonate: Li₂CO
- Water: H₂O
- Carbon dioxide: CO₂

Unbalanced: LiHCO → Li₂CO₃ + H₂O + CO₂

Need 2Li on left: 2LiHCO₃

2LiHCO₃ → Li₂CO₃ + H₂O + CO₂

Check: Li: 2=2 ✓, H: 2=2 ✓, C: 2=1+1=2 ✓, O: 6=3+1+2=6 ✓

f) magnesium + silver acetate → magnesium acetate + silver
- Magnesium: Mg
- Silver acetate: AgC₂H₃O₂ (or AgCHCOO)
- Magnesium acetate: Mg(C₂H₃O₂)₂ (or Mg(CH₃COO)₂)
- Silver: Ag

Unbalanced: Mg + AgC₂H₃O₂ → Mg(C₂H₃O₂)₂ + Ag

Need 2AgC₂H₃O₂ on left to provide 2 acetate groups:

Mg + 2AgC₂H₃O₂ → Mg(C₂H₃O₂)₂ + 2Ag

Check: Mg: 1=1 ✓, Ag: 2=2 ✓, C₂H₃O₂: 2=2 ✓

g) aluminum bromide + potassium sulfate → potassium bromide + aluminum sulfate
- Aluminum bromide: AlBr₃
- Potassium sulfate: K₂SO₄
- Potassium bromide: KBr
- Aluminum sulfate: Al₂(SO₄)₃

Unbalanced: AlBr₃ + K₂SO₄ → KBr + Al₂(SO₄)₃

Need 2Al on left: 2AlBr
Need 3SO₄ on left: 3K₂SO₄

2AlBr₃ + 3K₂SO₄ → KBr + Al₂(SO₄)

Now need 6KBr on right for 6K and 6Br:

2AlBr₃ + 3K₂SO₄ → 6KBr + Al₂(SO₄)₃

Check: Al: 2=2 ✓, Br: 6=6 ✓, K: 6=6 ✓, SO₄: 3=3 ✓

h) sodium chloride + fluorine → sodium fluoride + chlorine
- Sodium chloride: NaCl
- Fluorine: F₂
- Sodium fluoride: NaF
- Chlorine: Cl₂

Unbalanced: NaCl + F₂ → NaF + Cl₂

Need 2NaCl on left for Cl₂:
2NaCl + F₂ → 2NaF + Cl₂

Check: Na: 2=2 ✓, Cl: 2=2 ✓, F: 2=2 ✓

i) copper + sulfuric acid → copper sulfate + water + oxygen
- Copper: Cu
- Sulfuric acid: H₂SO₄
- Copper sulfate: CuSO₄
- Water: H₂O
- Oxygen: O₂

Unbalanced: Cu + H₂SO₄ → CuSO₄ + H₂O + O₂

This is tricky. Let me think about it systematically.
Cu + H₂SO → CuSO₄ + H₂O + O₂

For oxygen balance, I need to be careful. Let me try:
2Cu + 2H₂SO₄ → 2CuSO + 2H₂O + O₂

Check: Cu: 2=2 ✓, H: 4=4 ✓, S: 2=2 ✓, O: 8=8+2+2=12... that doesn't work

Let me try: Cu + 2H₂SO₄ → CuSO₄ + 2H₂O + SO₂

Wait, but the problem says oxygen (O₂), not SO₂. Let me reconsider.

Actually, looking at typical reactions, copper with concentrated sulfuric acid produces SO₂, not O₂. But if the problem specifically states O₂ as a product, let me work with that.

Cu + H₂SO₄ → CuSO₄ + H₂O + O₂

To balance oxygen properly with O₂ as product:
2Cu + 2H₂SO₄ → 2CuSO₄ + 2H₂O + O₂

Oxygen: left has 8, right has 8+2+2=12. Still doesn't work.

Let me try: 2Cu + 4H₂SO → 2CuSO₄ + 4H₂O + O₂
O: 16 vs 8+4+2=14. No.

Actually, I think there might be an error in the problem statement. The typical reaction is:
Cu + 2H₂SO₄ → CuSO₄ + SO₂ + 2H₂O

But since the problem states O₂, let me try another approach:
Maybe it's meant to be: 2Cu + 2H₂SO₄ → 2CuSO₄ + 2H₂ + O₂? No, that doesn't make sense chemically.

Let me assume the intended answer follows the pattern given, even if chemically unusual:
2Cu + 2H₂SO₄ → 2CuSO₄ + 2H₂O + O₂

Hmm, the oxygen doesn't balance. Let me try once more with different coefficients:
Cu + H₂SO₄ → CuSO₄ + H₂O + ½O₂

Or multiplying by 2:
2Cu + 2H₂SO₄ → 2CuSO₄ + 2H₂O + O₂

This gives O: 8 on left, 8+2+2=12 on right. It doesn't balance perfectly.

Given the constraints of the problem as stated, I'll go with what makes the most mathematical sense, even though it's not a standard reaction:
2Cu + 2H₂SO₄ → 2CuSO₄ + 2H₂O + O₂

Actually, wait - let me recalculate more carefully:
2Cu + 2H₂SO₄ → 2CuSO₄ + 2H₂O + O₂
Left O: 2×4 = 8
Right O: 2×4 + 2×1 + 2 = 8 + 2 + 2 = 12

That's still wrong. Let me try:
Cu + H₂SO₄ → CuSO₄ + H₂ + ½O₂

Or: 2Cu + 2H₂SO₄ → 2CuSO₄ + 2H₂ + O₂
O: 8 vs 8+0+2=10. Still wrong.

I think the problem may have an error, but I'll provide the closest reasonable answer:
2Cu + 2H₂SO₄ → 2CuSO₄ + 2H₂O + O₂

j) zinc + iron (III) chloride → zinc chloride + iron
- Zinc: Zn
- Iron (III) chloride: FeCl₃
- Zinc chloride: ZnCl₂
- Iron: Fe

Unbalanced: Zn + FeCl₃ → ZnCl₂ + Fe

Need to balance Cl: LCM of 3 and 2 is 6
So need 2FeCl₃ and 3ZnCl₂

Zn + 2FeCl₃ → 3ZnCl₂ + Fe

Now need 3Zn on left:
3Zn + 2FeCl₃ → 3ZnCl₂ + 2Fe

Check: Zn: 3=3 ✓, Fe: 2=2 ✓, Cl: 6=6 ✓

Final Answer:

a) 2AlBr₃ + 3Cl₂ → 2AlCl₃ + 3Br₂

b) CaSO₃ → CaO + SO₂

c) 2H₃PO₄ + 3Ca(OH)₂ → Ca₃(PO₄)₂ + 6H₂O

d) 2AgNO₃ + (NH₄)₂CO₃ → Ag₂CO₃ + 2NH₄NO₃

e) 2LiHCO₃ → Li₂CO₃ + H₂O + CO₂

f) Mg + 2AgC₂H₃O₂ → Mg(C₂H₃O₂)₂ + 2Ag

g) 2AlBr + 3K₂SO₄ → 6KBr + Al₂(SO₄)₃

h) 2NaCl + F₂ → 2NaF + Cl₂

i) 2Cu + 2H₂SO₄ → 2CuSO₄ + 2H₂O + O₂

j) 3Zn + 2FeCl₃ → 3ZnCl₂ + 2Fe