kinetics Flashcards
(8 cards)
what is the meaning of the rate of reaction?
change in concentration per unit time.
what is the meaning of activation energy?
The minimum energy particles need to react.
What effect does temperature have on the rate of reaction and why?
The higher the temperature the faster the rate of reaction.
Because particles move faster and collide more often.
Many more particles have more energy so more have E ≥ Eact. Thus they are more likely to react when they collide and so there are more frequent successful collisions.
What affect does the concentration have on the rate of reaction and why?
A greater concentration means a faster rate of reaction.
Because there are more reacting particles in a given volume and so particles are closer together. Thus there are more frequent successful collisions.
What affect does the pressure have on the rate of reaction and why?
A greater pressure means a faster rate of reaction.
Because particles are closer together as there are the same number of reacting particles in a smaller volume. Thus there are more frequent successful collisions.
What affect does the surface area have on the rate of reaction and why?
A smaller surface area means a greater rate of reaction.
Because more particles are exposed on the surface thus there are more frequent successful collisions.
What affect does using a catalyst have on the rate of reaction and why?
Using a catalyst increases the rate of reaction.
Because catalysts work by providing an alternate reaction route of lower activation energy. Thus more particles have E ≥ Eact and so there are more frequent successful collisions.
What is a catalyst?
A catalyst is a substance that increases the rate of a chemical reaction without being changed in chemical composition or amount.
