Physical - Kinetics Flashcards
What is activation energy?
The minimum amount of energy that colliding particles need to start a reaction
What is the symbol for activation energy?
Ea
What is an endothermic reaction?
Heat energy is taken the from surroundings and absorbed by the reactants.
Energy is put in.
What is an exothermic reaction?
Heat energy is released from the reactants to the surroundings.
Energy is removed
What is the collision theory?
The collision theory states that for a reaction to occur three criteria must be met, these are:
- particles must collide
- particles must have sufficient energy (activation energy)
- particles must collide with the correct orientation
What are the five factors that affect the rate of reaction?
1- catalysts
2- surface area
3- concentration
4- pressure
5- temperature
How does surface area affect the rate of reaction?
Having a higher surface area means that there is more particles available to collide and so the collision frequency is higher, meaning there is a faster rate of reaction.
How does concentration affect the rate of reaction?
The more concentrated a solution is, the more particles there are that can react, because of this the amount of that particles will collide and therefore react will be increased, leading to a higher rate of reaction.
How does pressure affect the rate of a reaction?
The higher the pressure the higher the rate of reaction will be,because the particles are closer to each other their amount of collisions will be much higher.
How does temperature affect the rate of reaction?
The higher the temperature, the faster the rate of a reaction. At higher temperatures the particles will have more energy so they move faster and are more likely to collide with other particles.
At higher temperatures more particles will have the required activation energy to react due to them sewing more energy.
How do catalysts affect the rate of a reaction?
They speed up a reaction by providing an alternative route for the reaction to take place, therefore catalysts lower the activation energy of a reaction, meaning less energy is needed for a reaction to take place.
