Why is it important to balance a chemical equation by including the correct coefficients?

• A. To change the physical state of the reactants
• B. To increase the rate of the chemical reaction
• C. To make the reaction produce more energy
• D. To ensure the law of conservation of mass is obeyed

Answer: (D)

Verified step by step guidance

1. Understand that a chemical equation represents a chemical reaction, showing reactants on the left and products on the right.
2. Recall the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction.
3. Recognize that balancing a chemical equation means adjusting the coefficients (the numbers in front of molecules) so that the number of atoms of each element is the same on both sides of the equation.
4. Know that balancing does not change the physical states of reactants or products, nor does it directly affect the rate of reaction or the energy produced.
5. Therefore, the primary reason to balance a chemical equation is to ensure the law of conservation of mass is obeyed, meaning the total mass of reactants equals the total mass of products.