Flashcards in Kinetecs Deck (71):

0

## Rates of chemical change

###
Change in the concentration of a specific element over a period of time

Units of M per second

See the book for practice

1

## Rate law

### Rate=k[A]^n

2

## Instantanteous Rate

###
Limit as (t-initial)+(t-final) approaches the designated time

In Δ[elementConcentration]/Δt

3

## First order reactant

###
The rate varies directly with the concentration of reactant-A, forms a linear curve

Rate=k[A]^1

4

## Second order reactant

###
The rate of the reaction changes exponentially with a change in the concentration of the A reactant

Rate=k[A]^2

5

## Reaction order for multiples reactants

###
Rate=k*([A]^m)*([B]^n)

The order of the individual reactant remains unchanged in the reaction, only the k-value changes (depends on the how many, as well as which, reactants factor into the problem here

6

## Integrated rate Law

### The concentrations of the reactants is related to time time

7

## First order integrate rate law

###
Natrual log [A] as a ratio to its original concentration for the simplest linear function

Ln([A]sub-t)/([A]sub-0)=-k*t

Write it out for practice

8

## Second-order integrated rate law

###
Describes the reciprocal of the concentration of [A] in terms of 't'

Basically just the inverse of the zero-order law

1/([A]sub-t)=-k*t +(1/[A]sub-0)

9

## Zero-order integrated rate law

###
Describes concentration as a linear function of (t)

[A]sub-t= -k*t +[A]sub-0

10

## Half life of a reaction

###
T sub-1/2= 0.693/k

Or

T sub-1/2= ([A]sub-0)/2k

11

## Arrhenius Equation

###
k= Ae^ ((-Ea)/RT)

A=frequency factor, individual to each reaction

Ea=activation energy

R= gas constant

T= temperature in kelvin

12

## Activation energy

### Energy that much be accumulated for the reaction to take plac

13

## Activated complex (transition state)

### The high energy state all molecules go through to go from reactants to products

14

##
Frequency factor (A)

### Number of time the reactants approach the activation energy level per minute

15

## Exponential factor

###
e^(-Ea/RT)

Represents a number 0 through 1 represents the fraction of molecules that have enough energy to participate in the reaction

16

## Arrhenius plot

###
Linear equation that represents the relationship between the temperature and the 'k-value'

Ln k=-Ea/R*(1/T) +ln A

17

## Arrhenius Equation (two point form)

### Ln (k2/k1)=Ea/R*(1/T1-1/T2)

18

## Collision Model

### The reaction in question calls for an energetic collision between two molecules

19

## Orientation factor (p)

### Numerical representation of the angle at which the molecules must collide with one another for the reaction to occur

20

## Collision frequency (z)

### Number of particle collisions that occur per unit of time

21

## K-value from Collision model

###
k=p*z*(exponentialFactor)

Write it out

22

## Reaction mechanism

### Series of individual chemical equations by which an overall chemical reaction occurs

23

## Elementary step

### The simplest possible step, chemical equation) into which an entire reaction mechanism can always be broken down

24

## Law of elementary steps in reaction mechanisms

### An entire reaction mechanism can always be broken down into one simple chemical equation that describes the entire process, known as the elementary step

25

## Reaction intermediate

### A molecule formed in an elementary step of a reaction mechanism but broken down by another reaction mechanism's elementary step

26

## Molecularity

### Number of reactant particles involved in a step

27

## Unimolecular reaction

### Only one reactant is required

28

## Bimolecular

### Two reactants are required

29

## Termolecular

###
Elementary steps in which three reactant particles collide,

Very rare to occur

30

## Rate-determining step

### The slowest step in the reaction mechanism

31

## Activation energy in reaction mechanisms

### Each require a little more energy, constant energy must be supplied

32

## Instantanteous Rate

###
Limit as (t-initial)+(t-final) approaches the designated time

In Δ[elementConcentration]/Δt

33

## Reaction order for multiples reactants

### Rate=k*[A]^m*[B]^n

34

## First order integrate rate law

###
Ln([A]sub-t)/([A]sub-0)=-k*t

Write it out for practice

35

## Second-order integrated rate law

### 1/([A]sub-t)=-k*t +(1/[A]sub-0)

36

## Zero-order integrated rate law

### [A]sub-t= -k*t +[A]sub-0

37

## Half life of a reaction

###
T sub-1/2= 0.693/k

Or

T sub-1/2= ([A]sub-0)/2k

38

## Arrhenius Equation

###
k= Ae^ ((-Ea)/RT)

Or ln(k)=ln(A)-(Ea/RT)

A=frequency factor, individual to each reaction

Ea=activation energy (in kJ/mol)

R= gas constant

T= temperature in kelvin

39

## Activation energy

### Energy that much be accumulated for the reaction to take plac

40

## Activated complex (transition state)

### The high energy state all molecules go through to go from reactants to products

41

##
Frequency factor (A)

### Number of time the reactants approach the activation energy level per minute

42

## Exponential factor

###
e^(-Ea/RT)

Represents a number 0 through 1 represents the fraction of molecules that have enough energy to participate in the reaction

43

## Arrhenius plot

###
Linear equation that represents the relationship between the temperature and the 'k-value'

Ln k=-Ea/R*(1/T) +ln A

44

## Arrhenius Equation (two point form)

### Ln (k2/k1)=Ea/R*(1/T1-1/T2)

45

## Collision Model

### The reaction in question calls for an energetic collision between two molecules

46

## Orientation factor (p)

47

## Collision frequency (z)

### Number of particle collisions that occur per unit of time

48

## K-value from Collision model

###
k=p*z*(exponentialFactor)

Write it out

49

## Reaction mechanism

### Series of individual chemical equations by which an overall chemical reaction occurs

50

## Elementary step

51

## Law of elementary steps in reaction mechanisms

52

## Reaction intermediate

53

## Molecularity

### Number of reactant particles involved in a step

54

## Unimolecular reaction

### Only one reactant is required

55

## Bimolecular

### Two reactants are required

56

## Reaction Order

###
Power 'n' to which the concentration is raised in the rate formula, determines the effect the concentration of that product has on the rate.

The 'n' in

Rate=k*[A]^n

57

## Zero order reactant

###
Rate=k*[A]^0

The rate is independent of the concentration of that particular reactant

58

## Reaction order for a catalyst

### Always zero

59

## Overall rates of reaction

###
Same as the rate of a reactant with a single coefficient

60

## Individual reactant rate

### Same as the overall reaction rate multiplied by its coefficient

61

## Reaction rate when coefficient is multiplied

### The rate is multiplied by that same value

62

## Approximating reactant order

###
Graph- value=zeroOrder, linear=firstOrder, exponential=secondOrder

Algebra- [A]^x=OverallRate/k, x-is reactant order

63

## Approximating k-value

### k=Rate/[A]^x

64

## When graphing concentration vs time

###
Use arhennious equations

[A](t)

65

## Catalyst mechanism of action

### Lowers the activation energy required for the reaction to take place

66

## Activating energy from the k-value

### Ea=[Ln(k)-Ln(A)]*(RT)

67

## Reaction enthalpy ΔH

### The net energy change when the reactants are transformed into products

68

## Termolecular

###
Elementary steps in which three reactant particles collide,

Very rare to occur

69

## Rate-determining step

### The slowest step in the reaction mechanism

70