Balancing Equations Race

Balancing Equations Race

The Correct Answer and Explanation is:

Balanced Equations:

1. C₃H₈ + 5 O₂ → 3 CO₂ + 4 H₂O
2. 2 Al + Fe₃N₂ → 2 AlN + 3 Fe
3. 2 Na + Cl₂ → 2 NaCl
4. 2 H₂O₂ → 2 H₂O + O₂
5. C₆H₁₂O₆ + 6 O₂ → 6 H₂O + 6 CO₂
6. C₇H₈ + 9 O₂ → 4 H₂O + 7 CO₂
7. 2 NaClO₃ → 2 NaCl + 3 O₂
8. 2 (NH₄)₃PO₄ + 3 Pb(NO₃)₄ → 2 Pb₃(PO₄)₄ + 12 NH₄NO₃
9. 2 BF₃ + 3 Li₂SO₃ → B₂(SO₃)₃ + 6 LiF
10. C₇H₁₆ + 11 O₂ → 7 CO₂ + 8 H₂O
11. 3 CaCO₃ + 2 H₃PO₄ → Ca₃(PO₄)₂ + 3 H₂CO₃
12. 2 Ag₂S → 4 Ag + S₂
13. 3 KBr + Fe(OH)₃ → 3 KOH + FeBr₃
14. 2 KNO₃ + H₂CO₃ → K₂CO₃ + 2 HNO₃
15. Pb(OH)₄ + CuO → PbO₂ + Cu(OH)₂
16. Cr(NO₂)₂ + (NH₄)₂SO₄ → CrSO₄ + 2 NH₄NO₂
17. 6 KOH + 2 Co(PO₄)₂ → 2 K₃PO₄ + 2 Co(OH)₃
18. Sn(NO₂)₄ + 2 Pt₃N₄ → Sn₃N₄ + 4 Pt(NO₂)₄
19. B₂Br₆ + 6 HNO₃ → 2 B(NO₃)₃ + 6 HBr
20. 3 ZnS + 2 AlP → Zn₃P₂ + Al₂S₃

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Explanation

Balancing chemical equations ensures that the Law of Conservation of Mass is obeyed—meaning atoms are neither created nor destroyed in a chemical reaction. Each side of a chemical equation must contain the same number of atoms of each element. This balance reflects physical reality: for every atom of a reactant that reacts, there must be a corresponding atom in the products.

To balance an equation, we change the coefficients (the numbers in front of compounds) rather than the subscripts (which define the compound itself). For example, to balance C₃H₈ + O₂ → CO₂ + H₂O, we first balance carbon atoms (C), then hydrogen (H), and finally oxygen (O). This methodical approach ensures that all atoms are accounted for without altering compound identities.

Some equations also involve polyatomic ions, which are groups of atoms that stay together during the reaction, like NO₃⁻ (nitrate) or SO₄²⁻ (sulfate). In these cases, treating the ion as a single unit often simplifies balancing.

Reactions can include synthesis, decomposition, single replacement, and double replacement, each with unique patterns. For instance, in a combustion reaction like C₇H₁₆ + O₂ → CO₂ + H₂O, hydrocarbons react with oxygen to produce carbon dioxide and water.

This worksheet combines a variety of such reaction types and provides excellent practice for mastering balancing skills. By accurately balancing these equations, students reinforce their understanding of atomic relationships, stoichiometry, and chemical behavior—all foundational to success in chemistry.