If the uncatalyzed reaction occurs in a single elementary step, which of the following statements is true?

• A. The reaction mechanism consists of multiple steps.
• B. The reaction must involve an intermediate species.
• C. The rate law for the reaction matches the stoichiometry of the overall reaction.
• D. The rate law cannot be determined from the reaction equation.

Answer: (C)

Verified step by step guidance

1. Understand that for an elementary reaction, the reaction occurs in a single step, meaning the molecularity of the step directly relates to the stoichiometry of the reaction.
2. Recall that the rate law for an elementary reaction can be written directly from the balanced chemical equation, where the rate depends on the concentration of reactants raised to the power of their stoichiometric coefficients.
3. Recognize that if the reaction is uncatalyzed and elementary, there are no intermediate species formed, and the mechanism does not consist of multiple steps.
4. Therefore, the rate law can be determined directly from the reaction equation and matches the stoichiometry of the overall reaction.
5. Conclude that the correct statement is: 'The rate law for the reaction matches the stoichiometry of the overall reaction.'