Which of the following processes is an example of the Law of Conservation of Mass?

• A. Evaporation of water from a lake
• B. Balancing a chemical equation
• C. Photosynthesis in plants
• D. Combustion of gasoline in an engine

Answer: (B)

Verified step by step guidance

1. Understand the Law of Conservation of Mass: This law states that mass is neither created nor destroyed in a chemical reaction. The total mass of reactants equals the total mass of products.
2. Consider the process of evaporation of water from a lake: In this physical change, water changes from liquid to gas, but the mass of water remains constant, as it is only changing state.
3. Examine the process of photosynthesis in plants: This is a chemical reaction where carbon dioxide and water are converted into glucose and oxygen. The mass of the reactants equals the mass of the products, demonstrating the conservation of mass.
4. Analyze the combustion of gasoline in an engine: This chemical reaction involves gasoline and oxygen producing carbon dioxide and water. The mass of the reactants equals the mass of the products, adhering to the conservation of mass.
5. Balancing a chemical equation: This process involves ensuring that the number of atoms for each element is the same on both sides of the equation, reflecting the Law of Conservation of Mass. It is a direct application of this law, as it ensures mass is conserved in the reaction.