Collision thoery Flashcards
What is the equation for rate?
Change in concentration / time taken
What are the units of rate?
mol dm-3 s-1
What is collision theory?
Reactants must collide in the correct orientation with enough energy t overcome the activation energy
How do you increase rate of reaction?
Increasing the frequency of collisions or energy of collisions
What factors effecting rate of reaction?
Concentration, surface area, catalyst, pressure and temperature
How does concentration affect rate of reaction?
If you increase concentration of a reactant, there are more particles in the same volume so they collide more frequently
How does surface area affect rate of reaction?
The reactant can only collide with particles on the surface so a greater SA for its mass so more frequent collisions
How does pressure affect rate of reaction?
The more gas particles in a given space, the higher the pressure so there are more gas particles in the same volume so collide more frequently
What is a catalyst?
A chemical that will speed up a chemical reaction but is recovered unchanged at the end of
How do catalysts affect the rate of reaction?
They provide an alternate pathway for the reaction with a lower activation energy
How does reducing the activation energy effect rate of reaction?
Particles are more likely to exceed the activation energy on collision so reaction rate increase
How are the two ways temperature can affect rate of reaction?
More frequent collisions and activation energy
How does temperature affect rate of collisions?
Heating the reaction mixture gives the particles more kinetic energy so particles move faster per unit time, so collide more frequently
How does temperature affect activation energy?
Particles have more energy and are more likely to exceed activation energy on collision, increasing rate of reactions
What are the 2 types of catalyst?
Homogenous and heterogenous
