kinetics Flashcards
define rates of reactions
rate of chemical reaction is defined as the change in concentration per unit of time
state general rate law formula
rate = k[A]^m[B]^n
what determine overall order of reaction
sum of m+n
describe method of initial rates
put rates over each other, cross cancel and find m and n
what is half life
Half life is the time required for a reactant to reach half of its original concentration
state the 3 formulas for first order reaction
rate = k[A] ln[A]= -kt + ln[A]initial t1/2 = ln2/k
state the 3 formulas for second order reaction
rate = k[A]^2 1/[A]= kt + 1/[A]initial t1/2= 1/k[A]initial
state the 3 formulas for zero order reaction
rate = k [A]= -kt + [A]initial t1/2 = [A]initial/2k
what does a reaction mechanism consist of
a series of elementary steps, sum = overall reaction
mechanism must agree with experimentally determined rate law * must test if plausible
what is temperature
describes random motion of particles in a substance
increasing temp =
increasing rate of chemical reaction
what is activation energy (Ea)
barrier that needs to be overcome for a reaction to occur
state the 2 collision formulas
ln(k) = -Ea/R 1/T + ln (A)
ln(k2/k1) = Ea/R (1/T1 - 1/T2)
R=8.3145 J/kmol
what is a catalyst
a substance that speeds up a reaction without being consumed itself ☆ lowers the Ea
name the 2 types of catalyst
homogenous
heterogenous
