Rate of Reaction
Define rate of reaction
The rate of a chemical reaction is the increase in concentration of products or the decrease in concentration of reactants per unit time.
How is the graph for change in mass set up?
Mass against time
Kinetics refers to?
Movement
A catalyst provides an alternate...
Collision Theory?
In order to react, particles must collide with kinetic energy greater than the activation energy and have the correct collision geometry.
What factors affect rate of reaction?
Temperature, concentration, particle size, pressure of gases, and catalyst.
Explain change in gas as a technique used for measuring rate of reaction
The reaction vessel can be placed directly upon a balance and the mass can be recorded against time by being hooked to a data collection set up.
Kinetics is the study of?
How fast the reaction goes
Does a catalyst lower the activation energy?
No
To have a successful reaction you need 2 factors:
Sufficient energy (greater than Ea)
Correct geometry
mol dm-3s-1
What are the techniques used for measuring rate of reaction?
Change in volume of gas produced, change in mass, change in transmission of light (colorimetry/spectrophotometry), change in concentration measured using titration, change in concentration measured using conductivity, clock reactions.
Movement in chemistry refers to?
The progress of a reaction
What does a catalyst do?
Increases the rate of the reaction without itself undergoing chemical change.
A graph for change in mass would be set up as
Mass against time
How does temperature increase rate of reaction?
Increasing the temperature increases the kinetic energy of the particles, increasing the temperature, you will increase the number of collisions.
Explain change in volume of gas produced as a technique for measuring rate of reaction.
You can collect the gas and measure the change in volume at regular time intervals. Collection can be done with a gas syringe or by water displacement in a burette.
Kinetic theory of matter?
All matter consists of particles which are in constant motion.
What is conductivity?
A measure of the number of ions in a solution.
How does a catalyst increase rate of reaction?
Provides an alternate route for the reaction with a lower activation energy; ensures that without raising the temperature, more particles have sufficient KE to overcome the Ea barrier.
What is quenching?
A substance that is introduced to stop the reaction at that moment; stopping the reaction at each time interval
Reaction mechanism is?
A sequence of bond breaking and bond making which suggests “how” the reaction happens.
Temperature is measured in?
Kelvin