Kinetics Flashcards
What is the reaction rate?
It is defined as the change in concentration of a reactant or product over time
What is the equation to calculate the reaction rate?
Reaction rate = change in concentration / unit time
What are the units for the reaction rate?
moldm^-3/s
What is the Collision theory?
Particles have to collide with at least the activation energy for a reaction to occur
What is the activation energy?
The minimum energy required for particles to successfully collide and for a reaction to happen
What are the factors that affect the reaction rate?
Surface area Catalyst Temperature Concentration Pressure
How does a catalyst affect the reaction rate?
A catalyst speeds up the reaction by providing an alternative route with a lower activation energy.
Therefore, more particles have at least the activation energy and this increases the reaction rate
What are the advantages of using a catalyst?
They speed up the reaction saving time
Lower temperatures are used which saves energy costs
What are the disadvantages of using a catalyst?
It is expensive
It is specific to a reaction
How does surface area affect the reaction rate?
Increasing the surface area means that the frequency of successful collisions increases.
Therefore, the reaction rate increases
How does temperature affect the reaction rate?
Small increases in temperature have large effects on the reaction rate because the proportion of particles with energy greater than the activation energy increases
How does concentration affect the reaction rate?
Increasing concentration increases the number of particles per unit volume. Therefore, the frequency of successful collisions increases
How does pressure affect the reaction rate?
Increasing pressure increaases the number of particles per unit volume because they are closer together.
Therefore, there is a greater chance of successful collisions
What is the area under a Maxwell-Boltzmann distribution curve?
Total number of molecules
What does the peak of a Maxwell-Boltzmann distribution curve represent?
Most probabe energy
The most likely energy of an single molecule
