Conservation in Reactions
How do balanced chemical equations show conservation of mass?
Reactants
Products
In a chemical reaction, matter is neither created nor destroyed. Let's consider the reaction that occurs when the methane gas fueling a bunsen burner combusts in the presence of oxygen. The products of this reaction are carbon dioxide and water.
During this reaction, one methane molecule combines with two oxygen molecules to form one carbon dioxide molecule and two water molecules.
Now let’s compare the atoms of the reactants to the atoms of the products. On the reactant side, the methane and oxygen together consist of 1 carbon, 4 hydrogens, and 4 oxygens. The same is true for the product side of the equation.
The carbon dioxide and water together consist of 1 carbon, 4 hydrogens, and 4 oxygens. When the equation is balanced, the same number of atoms for each of these elements must exist on both sides of this equation.
Matter was neither created nor destroyed. Click the Feature tab to practice balancing equations.