Which law is demonstrated when a chemical equation is balanced?

• A. Law of Conservation of Mass
• B. Law of Definite Proportions
• C. Law of Conservation of Energy
• D. Law of Multiple Proportions

Answer: (A)

Verified step by step guidance

1. Understand that balancing a chemical equation means making sure the number of atoms of each element is the same on both sides of the equation.
2. Recall that the Law of Conservation of Mass states that mass cannot be created or destroyed in a chemical reaction, so the total mass of reactants must equal the total mass of products.
3. Recognize that when you balance a chemical equation, you are applying this law by ensuring the same number of atoms (and thus the same mass) are present before and after the reaction.
4. Note that other laws listed, such as the Law of Definite Proportions, Law of Conservation of Energy, and Law of Multiple Proportions, describe different chemical principles and are not directly related to balancing equations.
5. Conclude that the process of balancing chemical equations directly demonstrates the Law of Conservation of Mass.