What principle does the law of conservation of mass illustrate in a chemical reaction?

The law of conservation of mass states that in a chemical reaction, the total mass of the reactants must equal the total mass of the products. This principle asserts that matter cannot be created or destroyed during a chemical process; rather, it simply transforms from one form to another. Therefore, when a reaction occurs, the atoms that make up the reactants are rearranged to form the products, but the total number of each type of atom remains unchanged.

In practical terms, if you start a reaction with a certain amount of mass in reactants, after the reaction has completed, you will find that the products will also have the same total mass measured. This concept is foundational in chemistry, as it underpins stoichiometry and the balanced equations that chemists use to represent reactions.

The other statements do not align with this principle. For instance, suggesting that mass can be created or destroyed contradicts the core idea of conservation. Similarly, the notion that products have greater mass overlooks the balance that must exist between reactants and products, while the idea that mass does not affect reaction rate pertains to a different aspect of chemical kinetics and not to mass conservation in reactions.