Which statement best describes the law of conservation of mass?

• A. Energy and mass are always conserved together in every chemical reaction.
• B. The mass of the products is always greater than the mass of the reactants.
• C. The total mass of reactants equals the total mass of products in a chemical reaction.
• D. Mass can be created or destroyed during a chemical reaction.

Answer: (C)

Verified step by step guidance

1. Understand that the law of conservation of mass states that mass cannot be created or destroyed in a chemical reaction.
2. Recognize that this means the total mass of the reactants before the reaction must be equal to the total mass of the products after the reaction.
3. Note that this law is fundamental to balancing chemical equations, ensuring that the number of atoms of each element is the same on both sides.
4. Be aware that energy conservation is a related but separate concept; the law of conservation of mass specifically addresses mass, not energy.
5. Eliminate incorrect statements by checking if they contradict the principle that mass remains constant during a chemical reaction.