Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

chemistry 1302 gen chem 2 > chapter 11: chemical kinetics > Flashcards

chapter 11: chemical kinetics Flashcards

1
Q

what is kinetics

A

concerned w/ the speed rates of rxns

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is rate

A

changes in quantity in a given period of time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is thermodynamics

A

tells the direction and extent of the reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is a state function

A

independent of the path

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

thermodynamics has nothing to do with

A

kinetics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how can you determine the rate of reactions

A

monitoring the change in concentration
- reactions slow down every time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the instantaneous rate

A

the slope of a line tangent to the curve at any point

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the initial rate

A

the instantaneous rate, t= 0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is a rate law

A

shows how the rate depends on the concentrations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is k

A

the rate constant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how do you determine the exponents

A

determined by the experiment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the rate law exponents

A

0,1,2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the overall reaction order

A

the sum of the orders w/ respect to each reactant in the rate law

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how do you write the rate

A

use the reactants k[A]^a[B]^b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are the units of rate constant

A

M^-1,S^-1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is zero order

A

changing conc. has no effect on the rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

first order

A

rate changes by the same factor as the conc( doubles the initial concentration doubles the rate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is second order

A

the rate changes by the square of the factor the concentration changes
- doubling the initial concentration quaduples the rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is another name for rate laws

A

differntial rate laws
- used to calculate reaction rates when given reactant conc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is integrated rate laws

A

used to calculate the amount of reactants left after a certain amount of time has passed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is the first order reaction equation

A 
ln[At] = -kt+ ln[A0] 
y = mx + b
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what are some characteristics of zero reactions

A

-rate=k[A]^0\
- doesn’t depend on concentration
- 2^0 =1, 3^0 -1
- M^1t^-1
equation: -kt + [A0]
slope = -k

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what can you use to find the order of a reaction depending on the exponent

A

M^1-n t^-1

24
Q

what is half life t1/2

A

time required for one half of a reactant to react
[A] @ 1/2 is one half the original then [At] = 0.5[A0]

25
what is the first order reaction 1/2 life equation
- does not depend on the initial concentration - 0.693/k = t/1/2
26
what is the second order reaction equation
1/[At] = kt + 1/[A0] y = mx + b
27
what is the half-life equation for second-order reactions
1\k[A0] = t1/2
28
what is the equation for a zero order 1/2 life equation
[A0] /2k
29
when do zero order reactions most likely occur
when a substance such as a metal surface or enzyme is required for a reaction to occur
30
what is the collision model
accounts for the observed characteristics of reaction rates - molecules need to collide to react
31
what are the 4 factors that affect rate
1. concentrations of reactants 2. physical state of reactants 3. temperate 4. structure and orientation of reacting particles
32
how concentrations of reactants affect rate
- increase in concentration = increase that the mlcls will collide = increase in rate ## Footnote -reducing volume / increasing pressure on gas = concentration increase
33
phyisical state of reactants and rate
- reactants that are more homogenous the faster it will react - reactants in diff. phases = limited area of contact - limited area = reactions that involve solids proceed faster if the surface area of the solid is increased
34
temperature and rates
- higher temp = more KE = molecules will collide more often and w/ greater energy ## Footnote - rate increases bc of temperature rising
35
structure and rates
- greater frequency of collisiosn = greater rate of reaction
36
for a collision to lead to a rxn what needs to occur
has to have enough energy to stretch bonds to form new bonds in other proper locations
37
what are effective collisions
collisions in which the 2 conditions are met (greater frequency + lead to reaction) - increase in EFFECTIVE collision = faster rate
38
what is activation energy
- Svante Arrhenius - energy that molecules possess in order to react
39
what is a reaction coordinate diagram
- very top of the hill is the transitions tate - right = products - left = reactants
40
what is the activated complex and activation energy barrier
- activated complex: species present at the transition state - activation energy barrier= the energy gap between the reactants and the activated complex
41
difference in Ea of the forward vs. reverse
Ea is always higher for endothermic proc3sses
42
what is the arrhenius equation
ln k = -Ea/R(1/T) + Ln A - T = temp in kelbin - Ea = activatio energy - R = 8.314 J/ mol k A = frequency factor
43
what is a frequency factor
the likelihood that collisions would occur w/ proper orientation for reaction
44
what arrhenius equation is used to evauluate 2 or more temps
ln k1/k2= Ea/R(1/t2 - 1/T1)
45
what does a balanced equattion not tell us
how the reaction occurs
46
what is the reaction mechanism
the sequence of events that describes the actual process of how reactants turn into products
47
what is each step known as in a reaction mechanism
elementary reaction
48
what is an INTERMEDIATE
substance that is formed first as a product then consumed as a reactant
49
what is molecularity
the number of reactants molecules in an elementary step
50
what are the different molecularitys
- unimolecular = k[A] - bimolecular = 2 - termolecular = 3
51
what happens in a mulistep process
one process will be slower than the others and this is the rate determining step
52
why is the slowest step the rate determining ste[
slowest step has the largest activation energy
53
what is a catalyst
a substance that changes the rate of a reaction w/out being permanently consumed - consumed in an early step in the reactants and then produced in the products at a later step
54
what is a homogenous catalyst
present in the same phase as the reactant molecules
55
what is a heterogenous catalyst
present in a different phase than the reactant molecules - catalyst can speed up a reaction by holding the reactants together and helping to break bonds
56
what is an enzyme
protein molecules that catalyze biological reactions - active site: the place of the reaction
57
what is sibstrate and the lock and key model
- substrate: substances that undergo reactoin at the site - lock and key model: enzymes are specific and they fit inside certain substrates

chemistry 1302 gen chem 2 (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions