Catalysts
Chemistry: AQA GCSE Higher, topic 6.1.6
Catalysts
Catalysts increase the rate of chemical reactions by lowering the activation energy. They do this by changing the reaction pathway.
Are catalysts used up in reactions?
- Catalysts are not used up during chemical reactions. This means that:
- They can be reused indefinitely.
- They are not found in chemical equations.
- But, catalysts will often need cleaning or regenerating, which has knock-on effects for energy expenditure and environmental impact.
What are some examples of catalysts?
- Different catalysts are appropriate for different reactions:
- Iron is used in the process that makes ammonia.
- Platinum and palladium are used in catalytic converters in cars.
- Enzymes catalyse reactions in biological systems.
What form do catalysts come in?
- Catalysts often come as powders, pellets or fine gauzes because these types of substance have particularly high surface areas.
Test yourself on Catalysts
Select the correct statement for each pair about catalysts.
Why do catalysts often come in the form of powders, pellets and fine gauzes?
What are the knock-on effects of catalysts needing regular cleaning or regenerating?
How do catalysts lower the activation energy needed for a chemical reaction?
Select the correct statement for each pair about catalysts