How does a chemical equation support the law of conservation of matter?
A chemical equation supports the law of conservation of matter because it shows that matter is neither created nor destroyed during a chemical reaction, only rearranged. In other words, the total mass of the reactants (substances on the left side of the equation) must equal the total mass of the products (substances on the right side of the equation). This fundamental principle is known as the law of conservation of matter.
To understand how a chemical equation supports this law, you need to understand how chemical equations are written. Let's take an example of a simple chemical reaction: the combustion of methane (CH4) in the presence of oxygen (O2) to produce carbon dioxide (CO2) and water (H2O).
The balanced chemical equation for this reaction is:
CH4 + 2O2 → CO2 + 2H2O
Each chemical formula in the equation represents the number and type of atoms present in that particular molecule. The numbers in front of the formulas, called coefficients, represent the ratio of molecules or moles involved in the reaction.
Now, let's examine the law of conservation of matter using this equation. On the left side of the equation, we have one molecule of methane (CH4) and two molecules of oxygen (O2). On the right side, we have one molecule of carbon dioxide (CO2) and two molecules of water (H2O).
To ensure that the law of conservation of matter is upheld, we must examine the number and type of atoms present in the reactants and products. In this example, we have:
Reactants:
Carbon: 1 atom
Hydrogen: 4 atoms
Oxygen: 4 atoms (2 atoms in each oxygen molecule)
Products:
Carbon: 1 atom
Hydrogen: 4 atoms
Oxygen: 4 atoms (2 atoms in each carbon dioxide molecule, and 4 atoms in each water molecule)
By comparing the number of atoms before and after the reaction, we can see that the total number of each type of atom remains the same: 1 carbon, 4 hydrogen, and 4 oxygen atoms in both reactants and products.
Therefore, the chemical equation for the combustion of methane supports the law of conservation of matter, as it demonstrates that the total number of atoms on both sides of the equation is preserved, and no atoms are created or destroyed during the reaction.