What is the initial-rate method for determining the rate law, and what data are typically collected?

• A. Observe color change over time to infer rate.
• B. Measure final concentration after reaction completes and compare to stoichiometric coefficients.
• C. Determine rate constant by integrating rate law.
• D. Measure initial reaction rate at t=0 for various known initial concentrations; data collected are initial rates vs initial concentrations to deduce reaction orders.

Answer: (D)