kinetics

Question 1

kinetics

Answer 1

study of rates of reactions

Question 2

activation energy (Ea)

Answer 2

kinetic energy required for reactants to collide in order for the reaction to occur

Question 3

what does the rate of a reaction correspond to

Answer 3

how many collisions take place over a given time

Question 4

Arrhenius Equation

Answer 4

K= Ae^(-Ea/RT)
k is rate constant

Question 5

k in arrenius eqn

Answer 5

rate constant

Question 6

a in arrhenius eqn

Answer 6

frequency factor
- frequency of collisions between reactants

Question 7

Ea

Answer 7

activation energy

Question 8

R is arrhenius eqn

Answer 8

gas constant

Question 9

the rate constant can only be meaningfully affected by waht?

Answer 9

Ea and T

Question 10

If Ea/RT decreases what happens to k

Answer 10

rate constant decreases

Question 11

larger values of -(Ea/RT)

Answer 11

more negative, inverse relationship between Ea and K

Question 12

lower EA

Answer 12

higher rate of reaction

Question 13

temperature relationship to reaction rate (k)

Answer 13

proportional

Question 14

Ea relationship to reaction rate

Answer 14

inverse

Question 15

two ways to speed up a reaction

Answer 15

1. reduce Ea
2. heat up

Question 16

what other ways is K impacted

Answer 16

1. concentration of reactants
2. pressure in gas rxn (increase pressure increases rate)

Question 17

transition complex

Answer 17

brief period where covalent bonds in the reactants begin to weaken and bonds of products begin to form

Question 18

Ea relationship to transition complex

Answer 18

Ea is the amount of energy needed to reach the transition complex

Question 19

what is the highest energy point of the reaction

Answer 19

transition complex

Question 20

are transition complexes isolatable?

Answer 20

no, too unstable

Question 21

rate limiting step of a reaction

Answer 21

slowest step

Question 22

x axis of reaction coordinate diagrams

Answer 22

progress of reaction (time)

Question 23

y axis of reaction coordiate diagrams

Answer 23

energy

Question 24

Ea on reaction coordinate diagram

Answer 24

difference in E between reactants and highest point

Question 25

∆G on reaction coordinate diagram

Answer 25

difference in E between reactants and products

Question 26

energy of P

Answer 26

exergonic and ∆G< 0

Question 27

endegonic reaction on reaction coordinate diagram

Answer 27

P energy > reactant ∆G>0

Question 28

∆G

Answer 28

thermodynamic constant for a reaction that cannot be changed by kinetic parameters - decides spontaneity

Question 29

catalysts

Answer 29

substances that increase the rate of reaction by reducing the Ea

Question 30

how do catalysts decrease Ea

Answer 30

by stabilizing the transition state weaken bonds in reactants and change orientation to increase frequency of collisions

Question 31

T/F catalysts can affect thermodynamic parameters

Answer 31

no. they do not change ∆G or sponteneity

Question 32

heterogeneous catalys

Answer 32

different phase than the reactant

Question 33

homogenous catalyst

Answer 33

same phase as reactant

Question 34

rate law

Answer 34

rate= K[A]^x[B]^y - units of M/s

Question 35

order of a reaction

Answer 35

defined by the sum of the exponents

Question 36

zero order reaction

Answer 36

exponents of reactants sum to 0

Question 37

1 order reaction

Answer 37

exponents sum to one

Question 38

second order rxn

Answer 38

exponents of reactants sum to two

Question 39

third order rxn

Answer 39

exponents of reactants sum to three

Question 40

how to determine rate

Answer 40

look at changing concentrations to see how they affect the rate

Question 41

if the reactant is doubled and the rate is doubled what is the order

Answer 41

[A]^1

Question 42

if the reactant is doubled and the rate is quadroupled what is the order

Answer 42

[A]^2

Question 43

how to find K if you know the rates of both reactnats

Answer 43

K = rate/ [a]^x * [b]^y

Question 44

units of k for 0 order

Answer 44

m*s^-1 or m/s

Question 45

units of k for 1order

Answer 45

1/s

Question 46

units of k for 2 order

Answer 46

1/(m*s)

Question 47

units of k for 3 order

Answer 47

1/(m^2s)

Question 48

zero-order reactions

Answer 48

enzymes are saturated and there is too much reactant per enzyme - catalyst is rate limiting step - concentration of reagents is irrelevant

Question 49

first order reactions

Answer 49

radioactive decay and SN1 (depend on carbocation )

Question 50

second order raections

Answer 50

involve collision between two reactant molecules as in SN2

Question 51

second order raections

Answer 51

involve collision between two reactant molecules as in SN2

Question 52

rate law formula is based on

Answer 52

initial rate of the reaction

Question 53

graph of zero order rxn

Answer 53

linear

Question 54

graph of first order

Answer 54

non linear