Summary
Catalysts increase the rate of a reaction without being consumed in the process. Heterogeneous catalysts are in a different phase than the reactants, while homogeneous catalysts are in the same phase as the reactants.
- Catalyst — a substance that speeds up a chemical reaction without being consumed. Example: Iron in the Haber process.
- Heterogeneous Catalyst — a catalyst in a different phase than the reactants. Example: Platinum in catalytic converters.
- Homogeneous Catalyst — a catalyst in the same phase as the reactants. Example: Fe3+ ions in the iodine-peroxydisulfate reaction.
Exam Tips
Key Definitions to Remember
- Catalyst: A substance that increases the rate of a reaction without being consumed.
- Heterogeneous Catalyst: A catalyst in a different phase than the reactants.
- Homogeneous Catalyst: A catalyst in the same phase as the reactants.
Common Confusions
- Confusing the phase of the catalyst with the phase of the reactants.
- Misunderstanding the role of adsorption and desorption in heterogeneous catalysis.
Typical Exam Questions
- What is a catalyst? A substance that increases the rate of a reaction without being consumed.
- How does a heterogeneous catalyst work? It provides a surface for the reaction to occur, involving adsorption and desorption.
- What is an example of a homogeneous catalyst? Fe3+ ions in the iodine-peroxydisulfate reaction.
What Examiners Usually Test
- Understanding the difference between homogeneous and heterogeneous catalysts.
- The role of catalysts in lowering activation energy.
- Examples of catalytic processes like the Haber process and catalytic converters.