According to the Law of Conservation of Mass, what is conserved in every chemical reaction?

• A. Number of molecules
• B. Volume
• C. Mass
• D. Energy

Answer: (C)

Verified step by step guidance

1. Understand the Law of Conservation of Mass: It states that mass is neither created nor destroyed in a chemical reaction.
2. Recognize that this means the total mass of the reactants equals the total mass of the products.
3. Note that the number of molecules can change due to rearrangement of atoms, so it is not necessarily conserved.
4. Volume can change depending on the state of substances and reaction conditions, so it is not conserved.
5. Energy can be absorbed or released during reactions, so it is not conserved as mass is; therefore, mass is the conserved quantity.