Collision Theory Flashcards
What must happen for a reaction
The reacting particles must successfully colide
What is a successful reaction
All reactants have changed to products
What is a successful collision?
A successful collision happens when the reacting particles have sufdicenr energy
What is the activation energy?
The minimum energy rescting particles must have when they collide for the reaction to take place
What does increasing the rate of reaction do?
Increase the chance/frequency of successful collisions.
What are the four ways od changing a rate of reaction?
Temperature, concentration, surface area and catalyst.
What does temperature do to RoR
At a higher temperature the particles have more kinetic energy and move faster.
What does concentration do to RoR (pressure)
At a higher pressure there are more reacting particles in the same space
What does concentration do to RoR
Increasing the concetration increases the number of reacting particles
What does surface area do to RoR?
Breaking a solid into a smaller pieces increases the surface area.
What does a catalyst do to RoR
Adding a catalyst to the reaction lowers the activation energy of the reaction.
Without being used up itself in the reaction
What are rate graphs used for?
A graph is used to follow the course of reaction
What can comparing graphs do?
Show the difference in the rates of simliar reactions
What is the rate of reaction?
How quickly reactants are used up or products are produced
What is the equation for calculating the mean rate of reaction?
Mean rate= change in quantity of product or reactant divided by time taken
What is the unit for rate of reaction in a reaction involving a change in mass?
G/s
What is the unit for rate of reaction involving a vhange in volume?
Cm3/s
(Cubed)
What is activation energy
The minimum amount of energy colliding particles have to have before a reaction will take place
What effect does increasing concentration hage on the rate of reaction
Increases
Why does increasing concentration habe this effect
More reactant particles in the same volume lead to more frequent collisions
What effect does increasing pressure have on the rate of reaction
Increases
Why does increasing the pressure have this effect?
Less space between particles mean more frequent collisions
What effect does increasing the surfsce area have on rate of reaction?
Increases
Why does increasing surface area have this effect?
More reactant particles are exposed are able to collide lesding to more frequent collisions
What effect does temperature have on the rste of reaftion?
Increases
Why dows increasing the temperature have this effect?
Particles move faster and particles have the same activation energy so more collisions in a result
What is a catalyst?
A substance that increases the rate of reaction but is not used up in the reaction.
How do catalysts increase the rate of resction
Lowers the activation energy of the reaction so more collisions result in a reaction
