6.1.1 Calculating rates of reactions
6.1.2 Factors which affect the rates of chemical reactions
Collision theory & factors that affect the rate
How does increase in temperature affect the rate of reaction?
- ↑ KE – particles move faster
- ↑ frequency of successful collision
- ↑ particles reach required Ea
- ↑ rate
How does increase in concentration / pressure affect the rate of reaction?
- ↑ no of particles per unit vol
- ↑ frequency of successful collision
- ↑ particles reach required Ea
- ↑ rate
How does increase in SA affect the rate of reaction?
- ↑ no of particles exposed
- ↑ availability to react
- ↑ frequency of successful collision
- ↑ particles reach required Ea
- ↑ rate
6.1.3 Collision theory and activation energy
Activation energy (Ea) – min energy required to start a reaction
Collision theory – see 6.1.2 Factors which affect the rates of chemical reactions
6.1.4 Catalysts
Catalyst
- Speed up chemical reaction
- Provide different pathway which ↓Ea
- Not used up in chemical reaction
- Different reactions need different catalysts
Why is catalyst used in industrial process? (2)
- Not used up
- ↑ rate of reaction
- Small quantities needed
Scientists have developed catalysts which allow quicker reaction at lower temperature. How can this benefit manufacturer and the environment? (2)
- ↑ product obtained in shorter time
- ↓ fuel needed
- ↓ pollution caused by burning fuels