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Rate of reaction
Change in concentration of a reactant or product in a given time
Rates of reaction are affected by?
Concentration
Temperature
Surface area
Particle size
Catalyst
Define Collision theory
Reactions occur when reactant particles collide provided that they collide with a certain minimum kinetic energy, the activation energy
Does orientation matter
Yes, particles must collide with the correct orientation for a reaction to take place
What are some ways catalysts can interact with a reaction
May react to form an intermediate
It is later regenerated
What does a catalyst do
A catalyst lowers the activation energy of a reaction by providing an alternative route for the reaction with lower activation energy
Define a Heterogeneous catalyst
A catalyst that is in a different physical state to the reactants
Define a Homogeneous catalyst
The catalyst and reactant are in the same physical state
How does a heterogeneous catalyst work?
reactants absorbed onto surface of the catalyst and the reaction takes place then the products that are formed de absorb and diffuse away
What is the Boltzmann distribution
shows the no. of molecules with a particular energy, at one temp, often shown as a graph
Important features of the Boltzmann graph
Area under the curve = total no. of molecules
• No molecules have ZERO energy (curve starts at origin or 0,0)
• No MAXIMUM energy (curve not get to 0 on x-axis)
• ONLY molecules with energy greater than Ea can react
How would a catalyst effect the Boltzmann distribution
The Ea is lowered so a greater number of particles have greater energy than the Ea so an increased rate of reaction
Define Dynamic equilibrium
dynamic equilibrium is the equilibrium in a closed system when the rate of forward reaction = rate of reverse reaction
What are the characteristics of dynamic equilibrium
The concentrations of the reactants and products
do not change over time.
– rate of forward reaction = rate of reverse reaction
Note 
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