Kinetics Flashcards
What is a first order reaction?
The rate is directly proportional to the concentration of the reactant
What is a second order reaction?
The rate is proportional to the square of the concentration
How do you calculate rate constant (k)?
Rate/(Concentration of reactant 1 x concentration of reactant 2)
What are the units for a zero order reaction?
mol L-1 s-1
What are the units for a second order reaction?
L mol-1 s-1
What is the differential rate law for a first order reaction formula?
ln(R) = ln(R)o -kt
What is the integrated rate law for a second order reaction?
1/(R) = 1/(Ro) +kt
What is the half life equation for a first order reaction?
t1/2= ln2/k
What is the half life equation for a second order reaction?
t1/2 = 1/(Ro)xk
What is the exponential form of the arrhenius equation?
What is the formula for calculating activation energy from temperatures and rate constants?
Ea= ((k2/k1)xR)/(1/T2-1/T1)
How are temperatures in degrees celsius converted into kelvins for use in the Arrhenius equation?
Add 273.15
What is an elementary reaction?
A simple step in a complex reaction which occurs in a single collision
What is a heterogenous catalyst?
Substance which is not in the same state as reactants that affects the rate of reaction but is unchanged at the end eg Pt in the hydrogenation of alkenes
What is a homogenous catalyst?
Substance which is in the same phase as reactants that affects the rate of reaction but is unchanged at the end of the reaction eg. H+ in the hydration of alkenes to alcohols
What is a transition state?
A point of maximum energy on the reaction path between reactants and products
What is the activation energy?
Energy required by the reactants to reach the transistion state
What is the arrhenius equation?
Gives the relationship for the temperature dependence of the reaction rate constant
What is a reactive intermediate?
A species formed in one step and consumed in another
What is a rate determining step?
The slowest step in a reaction mechanism
What is an explosion?
A reaction which accelerates because the concentration of reactive intermediates increases with time
What is autocatalysis?
When the reaction product itself is the catalyst for a reaction
What is the process to complete the rate law for an overall reaction?
Rate law for slow step
Subsitute for intermediate
kK
k1
