Reaction Rates

Collisions make reactions

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Reactions happen through collisions; more concentration means more collisions.
• Many reactions decay exponentially: [A] = [A]₀e^(−kt).
• Half-life = ln 2 / k, independent of the starting amount.

Steps

1. Molecules in a box
2. Why crowding helps
3. Rates and half-lives
4. Set the half-life
5. Average rate
6. Fading bleach