Collision theory

Definition

Collision theory explains how and why chemical reactions occur by describing the conditions under which reactant particles must collide. Effective collisions require proper orientation and sufficient energy to overcome activation energy.

5 Must Know Facts For Your Next Test

1. For a reaction to occur, particles must collide with the correct orientation and sufficient energy.
2. The minimum amount of energy required for a reaction to occur is called the activation energy.
3. Increasing the temperature generally increases the reaction rate because particles have more kinetic energy, leading to more effective collisions.
4. Catalysts lower the activation energy needed for a reaction, increasing the rate without being consumed in the process.
5. The collision frequency, which is affected by concentration and temperature, plays a crucial role in determining reaction rates.

Review Questions

• What two conditions must be met for a collision between reactant particles to be effective?
• How does increasing temperature affect the rate of reaction according to collision theory?
• What role does activation energy play in collision theory?

Related terms

Activation Energy:

The minimum amount of energy that reacting particles must have for a successful collision leading to a chemical reaction.

Catalyst:

A substance that increases the rate of a chemical reaction by lowering its activation energy without being permanently changed.

Reaction Rate:

The speed at which reactants are converted into products in a chemical reaction.