4.3.1 Collision Theory Flashcards
A chemical reaction can only occur if…
…the reactant particles collide with enough energy.
What is the amount of energy the particles need to react called?
Activation energy
What two factors does the overall rate of reaction depend on?
- Collision frequency: how often do the particles collide with each other?
- Percentage success: what percentage of the collisions have enough energy?
What are four common factors affecting the rate of reaction?
- Solid surface area (collision frequency)
- Solution concentration (collision frequency)
- Temperature (percentage success)
- Catalysts (percentage success)
Why does a high solid surface area increase rate of reaction?
More surfaces of the solid are exposed and accessible to collisions. There are more frequent collisions and more frequent successful collisions.
Why does a high solution concentration increase rate of reaction?
There are more particles per unit volume. Therefore there are more frequent collisions and more successful collisions per unit time.
Why does a high temperature increase rate of reaction?
The particles have more kinetic energy, meaning the percentage of collisions with energy above activation energy is higher. This means there are more frequent successful collisions.
Why does a catalyst increase rate of reaction?
Catalysts provide an alternative route with a lower activation energy, so the percentage of collisions with enough energy is higher and there are more frequent successful collisions.
