What does the law of conservation of mass state?

• A. Mass can be created or destroyed in a reaction
• B. Mass cannot be created or destroyed in a chemical reaction
• C. Mass is always constant in physical reactions
• D. Mass can change forms but remains constant

Answer: (B)

The law of conservation of mass states that mass cannot be created or destroyed in a chemical reaction. This fundamental principle, established by Antoine Lavoisier in the 18th century, asserts that the total mass of reactants in a chemical reaction will always equal the total mass of the products. In other words, during a chemical process, atoms are rearranged, but the number and type of atoms remain constant, thus preserving the total mass.

The significance of this law is reflected in stoichiometry and chemical equations, where balancing equations relies on the premise that mass is conserved throughout the reaction. Understanding this law is crucial for studying reactions in chemistry, as it influences how reactions are interpreted and analyzed in terms of mass relationships.

While other options may seem related to concepts of mass, they do not accurately capture the essence of the law of conservation of mass as it applies specifically to chemical reactions.