kinetics save my exams Flashcards
xCollision theory
The collision theory states that for a chemical reaction to take place the particles need to collide with each other in the correct orientation and with enough energy
effective collision
-chemical reaction
-correct orientation
enough energy
ineffective collision
when particles collide in the wrong orientation or when they don’t have enough energy and bounce off each other without causing a chemical reaction
Increase in reaction rate
When more collisions per unit time take place, the number of particles with energy greater than the Ea increases
This causes an increase in the rate of reaction
collision frequency
number of collisions per unit time
activation energy
the reactant particles need to overcome a minimum amount of energy
end or eco larger ?
In exothermic reactions the reactants are higher in energy than the products
In endothermic reactions the reactants are lower in energy than the products
Therefore, the Ea in endothermic reactions is relatively larger than in exothermic reaction
the reaction will not take place if…
Even though particles collide with each other in the same orientation, if they don’t possess a minimum energy that corresponds to the Ea of that reaction
Therefore, for a collision to be effective the reactant particles must collide in the correct orientation AND possess a minimum energy equal to the Ea of that reaction
Catalysts and activation energy
A catalyst is a substance that increases the rate of reaction without taking part in the chemical reaction by providing the particles an alternative mechanism with a lower activation energy
This is a question that suggests or leads to a desired response due to the wording of it e.g. Did you see the knife? as opposed to Did you see a knife?
