AP Chemistry · Chapter 5 of 9

Kinetics

Model reaction rates with data, rate laws, and mechanism-level reasoning about collisions and activation energy.

Why this chapter matters

Kinetics explains how fast processes occur and which variables control speed, a core part of scientific prediction.

What you will learn

  • Determine reaction order and rate law from initial-rate data.
  • Calculate rate constants and use integrated-rate relationships for simple systems.
  • Explain how temperature, concentration, and catalysts influence rate through collision theory and activation energy.

Lessons in this chapter

  1. Rates from concentration-time dataExtract average and instantaneous rates with correct sign and units.
  2. Rate laws from experimentsInfer reaction orders using controlled concentration changes.
  3. Mechanisms and elementary stepsRelate proposed mechanisms to observed rate laws and intermediates.
  4. Temperature effects and Arrhenius modelConnect activation energy changes to rate constant behavior.

Study task

Use a three-trial initial-rate table to determine a rate law, solve for k, and evaluate whether a proposed mechanism is consistent.

Chapter checkpoint

If doubling [A] quadruples the rate while doubling [B] leaves rate unchanged, what rate law form fits the data?

The reaction is second order in A and zero order in B, so rate = k[A]^2.