Why does increasing temperature increase the rate of a reaction?

• A. Particles move faster
• B. They become more stable
• C. Activation energy increases
• D. Collisions become less frequent

Answer: (A)

Raising the temperature gives particles more kinetic energy, so they move faster. This speeds up the rate in two ways: collisions occur more often because faster particles sweep out more collisions per second, and a larger fraction of those collisions have enough energy to overcome the activation energy needed to react. If collisions don’t have enough energy, bonds don’t break and the reaction doesn’t proceed, so increasing temperature makes such collisions more likely. The idea that activation energy increases with temperature isn’t correct, and saying collisions become less frequent contradicts what happens when particles move faster.