Assess students' ability to analyze multi‑step chemical reaction mechanisms: identify elementary steps, intermediates, and molecularities; determine and justify the rate‑determining step; derive overall rate laws using steady‑state or pre‑equilibrium approximations; and calculate activation energies from temperature‑dependent rate data (Arrhenius analysis). Provide mechanisms and kinetic data; include evaluation of catalysts/inhibitors. Target: advanced Grade 9–12 students; emphasis on mechanistic reasoning and quantitative calculation.