What does the law of conservation of mass state?

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 means that matter cannot be created or destroyed; it can only change forms. Therefore, the mass of the substances before the reaction is the same as the mass of the substances after the reaction. This is a fundamental concept in chemistry that helps to demonstrate the practical implications of stoichiometry in chemical equations.

Options suggesting that mass can be created or destroyed are inconsistent with this law. The idea that mass could change based on reaction temperature also contradicts the principle, as temperature affects the energy state of the molecules but does not affect the mass itself. Thus, the law of conservation of mass serves as a foundational concept for understanding chemical reactions and their associated processes.