Balancing Chemical Equations

The Problem: The Unbalanced Recipe

In chemistry, a chemical equation is like a recipe. It tells us what ingredients (reactants) we need and what we'll make (products). For example, to make water, we combine Hydrogen and Oxygen: H₂ + O₂ → H₂O.

But there's a problem. A fundamental law of the universe, the Law of Conservation of Mass, states that matter cannot be created or destroyed. Atoms can't just appear or disappear!

Look at our recipe. We start with 2 Oxygen atoms (in O₂) but end up with only 1 (in H₂O). One Oxygen atom has vanished! This recipe is broken. We need to balance it.

The Solution: Using Coefficients

How do we fix the recipe? We can't change the molecules themselves (e.g., changing H₂O to H₂O₂ would make hydrogen peroxide, not water!). Instead, we change the amount of each molecule we use. We do this by adding numbers in front of them called coefficients.

Your mission is to add coefficients to balance the "chemical scale." The equation is balanced when the count for each type of atom is the same on both the reactant and product sides.

Practice: Combustion of Methane

Great! You've balanced a simple equation. Now let's try a slightly more complex one: the combustion of methane (natural gas). This reaction powers stoves and furnaces.

Pro Tip: A good strategy is to balance elements that appear in only one compound on each side first (like C and H here). Save elements that appear in multiple places (like O) for last.