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

Let’s go through each reaction one by one and figure out what type it is. We’ll use the definitions:

- Synthesis: Two or more things combine to make one product. (A + B → AB)
- Decomposition: One thing breaks down into two or more products. (AB → A + B)
- Combustion: A fuel (usually with C and H) reacts with O₂ to make CO₂ and H₂O.
- Single displacement: One element kicks another out of a compound. (A + BC → AC + B)
- Double displacement: Two compounds swap partners. (AB + CD → AD + CB)
- Acid-base: An acid and base react to form salt and water — but none of these look like that, so we’ll skip unless obvious.

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1) Na₃PO₄ + 3 KOH → 3 NaOH + K₃PO₄
→ The ions swapped: Na⁺ went with OH⁻, K⁺ went with PO₄³⁻ → Double displacement

2) MgCl₂ + Li₂CO₃ → MgCO₃ + 2 LiCl
→ Again, ions swapped: Mg²⁺ with CO₃²⁻, Li⁺ with Cl⁻ → Double displacement

3) C₆H₁₂ + 9 O₂ → 6 CO₂ + 6 H₂O
→ Hydrocarbon + oxygen → carbon dioxide + water → Combustion

4) Pb + FeSO₄ → PbSO₄ + Fe
→ Lead kicked iron out of its compound → Single displacement

5) CaCO₃ → CaO + CO₂
→ One compound broke into two → Decomposition

6) P₄ + 3 O₂ → 2 P₂O₃
→ Two elements combined to make one compound → Synthesis

7) 2 RbNO₃ + BeF₂ → Be(NO₃)₂ + 2 RbF
→ Ions swapped again → Double displacement

8) 2 AgNO₃ + Cu → Cu(NO₃)₂ + 2 Ag
→ Copper kicked silver out → Single displacement

9) C₃H₆O + 4 O₂ → 3 CO₂ + 3 H₂O
→ Organic molecule + oxygen → CO₂ + H₂O → Combustion

10) 2 C₅H₅ + Fe → Fe(C₅H₅)₂
→ Two molecules plus iron made one big compound → Synthesis

11) SeCl₆ + O₂ → SeO₂ + 3 Cl₂
→ Oxygen replaced chlorine in the compound? Wait — actually, selenium lost chlorines and gained oxygens, and chlorine became free. This looks like oxygen displaced chlorine → Single displacement? But wait — let’s check: SeCl₆ has Se bonded to 6 Cl. In products, Se is with O₂, and Cl is free. So oxygen took the place of chlorine? Actually, this might be better classified as single displacement if we think of O₂ displacing Cl from Se. But technically, it’s not a classic single displacement because O₂ isn’t replacing one atom — it’s changing the whole structure. Hmm… Alternatively, maybe it’s decomposition + synthesis? But looking at common classifications, this is often called single displacement when an element replaces part of a compound. Let’s stick with Single displacement for now — but note: some might argue it’s redox or other. For school level, likely Single displacement.

Wait — let me double-check: SeCl₆ → SeO₂ + 3Cl₂. That means Se changed from being with Cl to being with O, and Cl was released. O₂ came in and “kicked out” Cl. So yes — Single displacement.

12) 2 MgI₂ + Mn(SO₃)₂ → 2 MgSO₃ + MnI₄
→ Ions swapped: Mg²⁺ with SO₃²⁻, Mn⁴⁺ with I⁻ → Double displacement

13) O₃ → O· + O₂
→ One molecule broke apart → Decomposition

14) 2 NO₂ → 2 O₂ + N₂
→ One compound broke into two different substances → Decomposition

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Final Answer:

1) Double displacement
2) Double displacement
3) Combustion
4) Single displacement
5) Decomposition
6) Synthesis
7) Double displacement
8) Single displacement
9) Combustion
10) Synthesis
11) Single displacement
12) Double displacement
13) Decomposition
14) Decomposition