Topic 9 - Kinetics Flashcards
What is activation energy?
The minimum amount of energy that particles need to have in order to react when they collide is called activation energy.
What does collision theory state?
For a reaction to occur:
- particles must collide
- particles must have sufficient energy
- particles must collide with correct orientation
What is the equation used to calculate rate of reaction?
Rate = change in concentration/ time
Why do all reaction have an activation energy?
Any chemical reaction results in the breaking of some bonds and making new bonds.
Bonds have to be broken before new ones can be made.
Explain the effect does an increase in surface area have on the rate of reactions?
If the surface area is increased more particles will be on the surface and able to collide with particles of the other reactant, this increases the chance for collisions and therefore more successful collisions,thus increasing the rate of reaction.
Explain the effect does increasing the concentration have on the rate of reaction?
Increasing the concentration, increases the probability of a collision between reactant particles in a given time.
Thus increasing the frequency of successful collisions —> increasing rate of reaction.
Explain the effect of increasing of temperature on the rate of reaction?
See Boltzmann - maxwell curve for explanation.
At higher temperatures the particles are moving faster so collide more frequently
What is a catalyst?
A catalyst is a substance that increases the rate of a chemical reaction but is chemically unchanged at the end of the reaction
What is a heterogenous catalyst?
It’s a catalyst that is in a different phase to that of the reactants.
How does a catalyst speed up the rate of reaction?
It provides an alternative route for the reaction with a lower activation energy. this means more products can be made faster as less energy /temperature is needed.
