Kinetics and equilibrium Flashcards
What is collision theory
The number of particles colliding per second
What is activation energy
The minimum amount of energy needed to start a reaction
What factors can affect chemical reactions
Increasing concentration of a solution
Increasing the surface area
Increasing temperature
Using a catalyst
Increasing pressure of a gas
How does increasing the temperature increase the rate of reaction
So molecules have energy higher than the activation energy so when they collide reaction occurs
How does increasing concentration of a solution increase rate of reaction
As there are more molecules meaning they are closer together so frequently of collision increases
Describe the effect of increasing surface area
More particles are available to collide
What is a catalyst and how does it work
It’s a substance that speeds to a reaction without being used to it lowers activation energy and provides an alternative pathway
State what’s on y and X axis on a maxwell boltzmann graph
Y axis is fraction of particles with energy
X axis -energy
State the effect of temperature on a maxwell Boltzmann graph
The curve peak moves to right and is lower
Give some examples of catalyst used
Platinum and rhodium
What is meant by dynamic equlilbrium
The rate of foward and back reactions is equal and concentrations are constant
What is le chatlier principle
When the conditions on system in equilibrium are changed the equilibrium will move to oppose the change
If concentration in a dynamic equilibrium is changed what will the system do
The system will oppose the change by shifting to the side that hadnt been in effected by concentration change thereby increasing its yield
If the forward reaction is endothermic and the temperature is increased in a dynamic equilibrium what will occur
The system will oppose the change and will reduce the temperature thereby favouring the endothermic reaction
If the temperature is reduced in a dynamic equilibrium what will happen
The system will oppose the change by increasing the temperature and will favour the exothermic reaction
What effect does the addition of a catalyst have on equilibrium
It has no impact on the position but it reduces the time taken to reach equilibrium
If the pressure in an equilibrium is increased what will the system do
It will favour the side with the fewest number of miles
Give the conditions in the Haber process and state the reason why they are like that
Low temperature as the foward reaction is expthermic if temperature is lowered the equilibrium will shift to the exothermic direction so more ammonia is used
High pressure- fewer number of moles on the right hand side so increase in pressure means equilibrium willl shift to the right
Catalyst - iron catalyst is used
Why are compromise conditions used in the haber process
As to low temperature means rate of reaction would be to low
High pressure isn’t use as it’s to expensive and requires expensive equipment
Both conditions are used as they give a reasonable yield at a reasonable cost
What are benefits of using a catalyst in reactions like the haber process
Means reactions can be done at a Lower temperature
Gives fewer unwanted products
