Exam 2 Flashcards
what need to collide to react
reactants
what to collisions need to have to initiate a reaction
activation energy
molecules must collide in an orientation that can lead to an rearrangement of the atoms
steric factor
effective collisions lead to the formation of an ______ ________ which is also known as the _______ _______
activated complex
transition state
Arrhenius equation
k=Axe^-Ea/ RT
what plot of the Arrhenius equation gives a straight line
ln(k) verus 1/T
slope -Ea/R
intercept= ln(A)
Arrhenius equation used to find activation energy
Ea= (-R*lnk2/k1)/ (1/T2 - 1/T1)
Arrhenius equation used to find rate constant
ln k2/k1 = -Ea/R (1/T2 - 1/T2)
what is a sequence of molecular events, or reaction steps, that defines the pathway from reactants to products
reaction mechanism
what can be describes as a sequence of elementary reactions or elementary steps
overall reaction
the overall reaction describes the reaction stoichiometry but does not tell us how the reaction ________
proceeds
an _______ ________ is a single step based on one collision (describes behavior of molecule)
elementary reaction
what appears is the mechanism but not in the overall balanced equation
intermediate
what always sum up to overall reactions and can involve intermediates
elementary reactions
reactions are often classified by their ________
molarity
the experimentally observed rate law for an ______ _______ must depend on the ________ _________
overall reaction
reaction mechanism
the slowest step with determine the rate: called
rate determining step
the energy of reactants and products stays the same the ______ _______ changes
transition state
what affects the reaction rate but is not consumed
catalyst
the ______ is the same before and after the reaction
catalyst
can the catalyst be a part of the rate law
yes
what type of catalyst can be in the same phase as the reaction / reactants
Homogeneous
what type of catalyst is in a different phase than the reaction/ reactants
heterogeneous
are enzymes a separate class of catalysts
yes
a mixture where [reactants] and [products] are in an equilibrium state is called an
equilibrium mixture
chemical equilibrium is a
dynamic equilibrium
in a dynamin equilibrium there is no _______ __________ which means forward and reverse rates are ________
net conversion
equal
a reaction that occurs in both directions is called a
reversible reaction
strictly: all reactions are _______
But: we call reactions that proceed nearly to completion __________
reversible
irreversible
Kc or equilibrium constant equation
Kf/Kr
Kc is __________
dimensionelss
Kc will always be the ________ at a particular temperature
same
Qc reaction quotient equation
Qc=[c]^c t [D]^d t / [A]^a t [B]^b t
Kc reaction quotient equation
[C]^c eq [ D]^d eq / [A] ^a eq [B]^b eq