C18- Further Kinetics Flashcards
What is the rate of reaction?
The rate of reaction is defined as the change in concentration of reactants per unit of time.
What is activation energy?
Minimum energy amount of energy required that particles have to have when colliding for a reaction to take place.
How does temperature affect rate of reaction?
Rate of reaction is higher at higher temperatures due to particles moving faster so more collisions with greater energy.
How does concentration affect the rate of reaction?
Increasing concentration causes increases in rate of reaction as there will be more particles in the same volume therefore more collisions.
How does surface area affect the rate of reaction?
Increase surface area increases rate of reaction as more particles are exposed to the other reactants, meaning more collisions.
Does adding a catalyst affect the rate of reaction?
Increases rate of reaction without being used up as provides an alternative route for the reaction with a lower activation energy. Larger proportion of collisions will be successful.
How do you calculate total order?
Add the separate orders of the reaction
What is the rate of reaction equation?
Rate= k[A]^m[B]^m
What does zero order mean?
The concentration of the species has no effect on the rate so forms a horizontal line.
What is a first order?
The concentration of the species and rate are directly proportional as conc doubles so does rate
What is a second order?
The rate is proportional to the concentration squared. Doubling the concentration will increase by rate of 4.
What is the rate constant?
The rate constant when the reaction temp in constant can be rearranged to find however has varying units.
The Arrhenius Equation
k= Ae^-EA/RT
lnk= -Ea/RT + lnA
How do you find activation energy?
Find gradient then = -EA/R so times by -8.31
What is the rate determining step/
Not all stages of a reaction occur at the same rate, but overall rate is determined by the slowest step. Therefore the rate equation contains the species involved in the stages up to including the rate determining step.
How do you determine rate equations?
Rate equations can be determined experimentally by monitoring concentration of reaction over time then find a tangent and find gradient to find out rate of reaction at that time.
