KINETICS Flashcards
What are rate laws used for?
Rate laws are used to relate the rate of a chemical rxn to concentrations of the reactant
What are rate laws dependant on?
Mechanisms (what breaks first, what bond forms first, any intermediate chemical species, etc…)
What is the kinetics definition of equilibrium?
Equilibrium is established when when both the forward and reverse rxns are occuring at the same rate (dG = 0)
What are reaction rates?
Reaction rates are a measure of the change of a chemical species as a function of time
What is the reaction rate formula?
What are the units for rate?
M/s
What are the factors which affect rate?
- Medium (surface area)
- Concentration
- Temperature
- Catalysis
What does more surface area do to the rate of a reaction?
Increases the rate of rxn
How does the reaction react when more material is readiily available?
It occurs faster
What happens to the rate of reaction when temperature is increased?
The higher the temperature the more molecules with sufficient energy to get over the energy barrier. Thus all elementary rxns have a faster rate at higher temperatures
How does a catalyst change the rate of a reaction?
A catalyst essentially changes the rxn mechanism for a rxn, allowing it to proceed at a faster rate by lowering the energy barrier between the reactants and products (activation energy)
What is the rate for zeroth order?
Rate = K
What is the integrated rate law for zeroth order?
[A] = [A]° - kt
What is the slope for zeroth order?
Negative
What is the half-life for zeroth order?
t1/2 = [A]° / 2K
What is the unit for zeroth order?
M/s
What is the rate for first order?
Rate = K[A]
What is the integrated rate law for first order?
ln[A] = ln[A]° - Kt