59-61 - Collisions and Types of Reactions Flashcards
What is collision theory?
The rate of reaction depends on how hard and how often particles collide
What three factors increase collisions?
Temperature
Concentration/pressure
Surface area
What two factors speed to collisions?
Temperature
Catalysts
Why are catalysts good for companies saving money?
Reactions take less time
Lower temperature required (less energy)
What are three disadvantages of catalysts?
- Can be expensive and difficult to clean
- Different products need different catalysts
- Can be poisoned by impurities
What is an exothermic reaction?
A reaction that transfers energy to the surroundings and results in a rise in temperature
What is an endothermic reaction?
A reaction that takes in heat and causes a fall in temperature
What are some examples of exothermic reactions?
Combustion
Neutralisation reactions
Oxidisation of sodium and water
What is an example of an endothermic reaction?
Thermal decomposition
What products use exothermic reactions?
Hand warmers
Self-heating cans
What products use endothermic reactions?
Injury packs (like ice packs)
What is a reversible reaction?
One that can be endo- or exothermic
What is an example of a reversible reaction?
Thermal decomposition of hydrated copper sulfate
How much energy is released in a reversible reaction compared to how much is absorbed?
Equal amount of energy released and absorbed
