Explain why an overall rate law may not reflect a single elementary step in a multi-step mechanism.

• A. The observed rate is determined by the rate-determining step and steady-state behavior of intermediates, not necessarily by the stoichiometry of any single step.
• B. The rate law always equals the first elementary step.
• C. The rate law is independent of mechanism.
• D. The rate law is determined by the products.

Answer: (A)