3.5 Chemical Kinetics Flashcards
Define rate of reaction
Change in concentration of a reactant or product per unit time
What is meant by order?
The order with respect to a reactant is the power to which the concentration of the reactant is raised to in the rate equation
What is meant by the rate constant, k?
The constant that links the rate of reaction with the concentration of reactants raised to the powers of their orders in the rate equation
What is meant by sampling and quenching?
- reaction where conc can be found in titration
- take small sample and place in salt and ice to stop reaction
- titrate or colorimeter
How to calculate rate
Chnage in conc
———————-
Time
Zero order graph
First order graph
Second order graph
Define half life
The time taken for the concentration of a reactant to reduce by half
What happens to k when temperature increases?
temp increase = rate increase = k increasw
What does a high value of k mean?
Fast reaction
What does a low value of k mean?
Slow reaction
What is meant by the rate determine step?
The slowest step in the multistep reaction mechanism
What is the Arrhenius equation used for?
To calculate the fraction of molecules that have energy above the activation energy, and from this the rate of reaction
Arrhenius equation
K = Ae ^(-Ea/RT)
