Practicals - effect on rate of reaction

Cards (13)

For a reaction to occur
1. The particles need to collide
2. The particles need to collide with enough energy to break the bonds in the reactant molecules, otherwise they will just bounce off each other
To change the rate of a reaction
1. Change the frequency of collisions between the reactant molecules
2. Change the energy with which the reactant molecules collide
Activation energy 
The minimum amount of energy that particles must have in order to react
Factors that impact collision theory
Concentration
Surface area
Temperature
Catalysts
Concentration 
Changes frequency of collisions
Surface area 
Changes frequency of collisions of substances
Temperature 
Increase in energy means increase reaction rate
Catalysts 
Lowers the activation energy
Concentration is low 
Fewer collisions, slower rate of reaction
Concentration is high 
More collisions, faster rate of reaction
Surface area to volume ratio is larger 
More frequent collisions
Substances are heated 
Particles gain kinetic energy and move faster, colliding more often, rate of reaction increases
Catalysts 
Increase the rate of a chemical reaction without being changed in chemical composition or amount
Provide an alternative reaction pathway which has a lower activation energy