3.1.1: The Equation Balancer
Master the art of balancing equations using the Law of Conservation of Mass
THE GOLDEN RULE
Atoms cannot be created or destroyed — only rearranged. Like Lego bricks, you must use the EXACT same pieces on both sides!
🎯 The Seesaw Principle
Imagine a chemical equation as a playground seesaw. If you have 4 hydrogen atoms on the left (reactants), you MUST have 4 hydrogen atoms on the right (products) — or the seesaw tips and crashes!
REACTANTS
PRODUCTS
PERFECT BALANCE
When balanced, the beam is level and glows green ✓
🧱 The Lego Analogy
Think of molecules as Lego constructions:
BEFORE (Reactants)
You have a "Methane Car" (CH₄) and "Oxygen Bikes" (O₂)
CH₄ + 2O₂
AFTER (Products)
You dismantle them and build "CO₂ Plane" and "Water Boats" (H₂O)
CO₂ + 2H₂O
The Rule: You use the EXACT same Lego bricks. No bricks appear from nowhere. None disappear!
⚖️ The Law of Conservation of Mass
This is Antoine Lavoisier's legacy: "Matter is neither created nor destroyed in chemical reactions."
Every carbon atom in your reactants will appear in your products. Every hydrogen. Every oxygen. They just swap partners and form new molecules.
C
1 → 1
H
4 → 4
O
4 → 4
Lesson Complete: You've Mastered Equation Balancing!
✓ Law of Conservation
Atoms are never created or destroyed
✓ State Symbols
(s), (l), (g), (aq)
✓ Balancing Technique
Adjust coefficients until atoms match
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