Select the correct answer.
Which of the following is true for balancing equations?
A. The number of products should be equal to the number of reactants.
B. The properties of products should be the same as the properties of reactants.
C. There must be an equal number of compounds on both sides of the equation.
D. There must be an equal number of atoms of each element on both sides of the equation.
Answer (2)
Balancing equations ensures the number of atoms of each element is the same on both sides.
Option A is false because the number of product molecules doesn't always equal the number of reactant molecules.
Option B is false because products and reactants have different properties.
Option C is false because the number of compounds can differ on each side.
Option D is true: equal atoms of each element on both sides is the key to balancing equations, so the answer is D .
Explanation
Understanding Balancing Equations When balancing chemical equations, we need to make sure that the number of atoms for each element is the same on both the reactant and product sides. This ensures that mass is conserved during the chemical reaction, which is a fundamental principle in chemistry.
Evaluating the Options Let's evaluate each option:
Option A: The number of product molecules does not necessarily equal the number of reactant molecules. For example, in the reaction 2 H 2 + O 2 → 2 H 2 O , there are 3 reactant molecules and 2 product molecules.
Option B: The properties of products are generally different from the properties of reactants. This is the basis of chemical reactions; reactants transform into products with different characteristics.
Option C: The number of compounds on both sides of the equation is not necessarily equal. In the same example, 2 H 2 + O 2 → 2 H 2 O , there are two compounds on the reactant side ( H 2 and O 2 ) and one compound on the product side ( H 2 O ).
Option D: The number of atoms of each element must be equal on both sides. This is the core principle of balancing equations.
Conclusion Therefore, the correct answer is that there must be an equal number of atoms of each element on both sides of the equation.
Examples
Balancing chemical equations is crucial in various real-life applications. For instance, in designing industrial chemical processes, ensuring the correct stoichiometry (the relationship between the relative quantities of reactants and products) is essential for maximizing yield and minimizing waste. In environmental science, balancing equations helps in understanding and mitigating pollution, such as in the design of catalytic converters in cars to reduce harmful emissions. In medicine, accurate balancing is needed for drug synthesis and understanding metabolic pathways.
The correct answer to the balancing equations question is option D, which states that there must be an equal number of atoms of each element on both sides of the equation. This principle is essential to uphold the law of conservation of mass during chemical reactions. Other options are incorrect for various reasons related to the definitions of reactants and products.
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