Rates of Reaction Flashcards
The smaller the particle size
the greater the surface area and the faster the reaction
The higher the concentration of the reaction
the faster the reaction
The higher the temperature
the faster the reaction
The higher the activation energy
The slower the reaction
For a chemical reaction to occur what are the two things needed
KINETIC ENERGY AND SPEED
Why is energy needed In a chemical reaction?
The energy is needed to overcome the repulsive force between the atoms and molecules and to start the breaking of bonds
What is activation energy
It is the minimum kinetic energy required for a SUCCESSFUL COLLISION to occur.
What is the unit for activation energy
(EA).
Explain what is meant by the term ‘activated complex’
It is when the reactant particles collide with the required activation energy.
Explain in terms of the collision theory how increasing SURFACE AREA increases the rate of reaction
Increase Collision Frequency: When the surface area is increased, the total area available for reactant particles to collide with each other also increases and this leads to a higher frequency of collisions of particles which can lead to a reaction.
Explain in terms of the collision theory how increasing the CONCENTRATION increases the rate of reaction
When the concentration of a reactant is increased, the number of particles also increases. This leads to an increase in the frequency of collisions between reactant particles which can lead to a reaction.
What is the formula for calculating rate?
1/time
(s-1)
An increase in pressure will
will increase the rate of the reaction
What is pressure
Pressure is a measure of the number of particles within a stated volume
What is temperature?
Temperature is a measure of the average kinetic energy of all the particles in a substance
An increase in temperature affects the rate of the reaction in two ways which are?
- Particles move faster and thus collide more regularly leading to an increase in successful collisions.
- More particles have equal to or more than the activation energy.
What is the formula for calculating time
1/rate
A catalyst is thought to help in the formation of?
The activated complex by helping the particles to collide with the correct geometry.
How does a catalyst affect the activation energy
Catalyst lowers the activation energy for a reaction, making it easier to form the activated complex
The enthalpy change for a reaction is the energy difference between?
Reactants and Products
What does the area under the graph in a kinetic energy distribution diagram represent?
The total number of molecules in a reaction
What is the name given to the unstable arrangement of atoms that forms at the peak of a potential energy diagram?
Activated complex
List things that increases the rate of the reaction
Adding a catalyst
Increase in Concentration
Increase in surface area
Increase in temperature
Decrease in particle size
Decrease in Activation Energy
If a reaction is endothermic what will happen to the temperature
The temperature will decrease
