Video narration
In exams, a “reaction mechanism” means the step‑by‑step pathway from reactants to products, not just the overall equation. Think of it like directions: you can’t jump from start to finish; you pass through turns and checkpoints. First, write the overall reaction. Then ask: which bonds must break, which new bonds must form, and where are electrons moving? Mechanisms track electron flow using curved arrows from an electron‑rich site to an electron‑poor site. Because many reactions can’t happen in one leap, we use intermediates—real, short‑lived species—and transition states—high‑energy “peaks” between steps. The slowest step is the rate‑determining step, and it controls the rate law. Finally, verify: if you add up all elementary steps, intermediates cancel out and you recover the overall balanced reaction. That’s the basic exam skill: follow electrons, identify intermediates, and check the sum.