Chapter 2 Chemical Kinetics

7/21/2019 Chapter 2 Chemical Kinetics

http://slidepdf.com/reader/full/chapter-2-chemical-kinetics 1/83

Chapter 2

Chemical

Kinetics1



• Reaction Rate Expression

• Factors affecting Reaction Rate

•Rate Law and Its Component

• Integrated Rate Laws:

- Zeroth, First and Second Order

Reactions

• Effect of Temperatre on Reaction Rate

SCOPE

!



• "#$e to determine simp$e reaction orders%

• "#$e to app$& the "rrhenis e'ation and rate

$aw in ca$c$ations%

• "#$e to identif& reaction mechanism and rate

determine step for a gi(en reaction%

LEARNING

OUTCOME

)



• *etermine reaction orders

• Ca$c$ate rate constants

• +rite expression for integrated rate $aws

• *etermine ha$f $ife

LEARNING

OUTCOMES



• "pp$& "rrhenis e'ation to ca$c$ate rate

constant or acti(ation energ&%

• Express rate $aw #ased on e$ementar&

reactions

• *eri(e rate $aw sing rate-determining step

LEARNING

OUTCOME



2.1 Reactin RateE!pressin• Chemica$ .inetics is the std& of the rate

of a reaction

• The reaction rate is the speed with which

reactants disappear and prodcts form

• Reaction rates are a$wa&s reported as

positi(e (a$es

• The nit is mo$ L /0 s /0

1



A"era#e$ Instantane%s an& InitialRates• Instantane%s rate'

slope of a line tangentto the curve at aparticular point (e)

• Initial rate'the instantaneous rateat the momentreactants are mixed (a)

• A"era#e rate'

slope of line joiningany two points (b, c, d)

2



2.1 Reactin RateE!pressin

•Rate of reaction: the change in concentrationsof reactants or products per unit time

• Consider this reaction → !

verage rate "

" delta " (#nal $ initial) concentration of

reactant%product

use & ' to express concentration in moles%liter

• verage rate " − "

•

3

[ ]t

Δ

Δ [ ]t

!

Δ

Δ

[ ]tΔ

Δ




Consider the reaction " 4

5

2 1 R ti R t





06

2 1 R ti R t



• The concentration of the reactant, ", decreases with

time

• The concentration of the prodct, 4, increases with

time

−

7conc of " at time t! / conc of " at time t08rate 9" ;t! / t0

;−

<7"8 <t

conc of 4 at time t! / conc of 4 at time t0rate 94 ;t!

/ t0

; <748

<t



00

2 1 R ti R t



• Ca$c$ate the a(erage rate at which 7"8

changes in the first 6 seconds

!% = 06- mo$ L-0 s-0

rate 9" <t

− <7"8

−97"8t;6 / 7"8t;6

6 s / 6 s

−96%61!5 mo$ L-0 / 6%626 mo$ L-0

6 s

-9-!% = 06- mo$ L-0 s-0

;

;

;

;

;



0!

2 1 R ti R t



• The rate at a partic$ar time is ca$$ed the

instantaneos rate

• This can #e determined from the s$ope of atangent to the cr(e

• For examp$e, from p$otting of 7"8 against time,

at t ; 6 s

rate ; -9s$ope of tangent $inedt

;-d7"8

; !%) = 06- mo$ L-0 s-0



0)

2 1 R ti R t



Reactin' A→

(upposed the reaction begins with 1*-- mol

*

t t "- there is 1*-- mol , no ! present*

t t "1- min, there is -*./ mol and -*0mol !

t t "/- min, there is -*2- mol and -*.-mol !*

Calculate average rate from t " - to t " 1-min*

average rate


0 mol/min0.026min0-min10

mol0-mol0.26

min0min10

)B(mol-)B(molΔt

B)Δ(moles

0at tmin10at t

==

−=

=

==



Consider :

C>

5C$

9a'?>

!O

9$ → C

>

5O>

9a'?>C$

9a'

4t&$ ch$oride 4t&$ a$coho$

+e can ca$c$ate the a(erage rate in termsof the disappearance of C>5C$%


0



C4H9Cl(aq)+ H2O(l) →

C4H9OH(aq)+HCl (aq)

Time (s) [ C4H9Cl ] (M)

6%6 6%0666

6%6 6%656066%6 6%63!606%6 6%620!66%6 6%6120)66%6 6%6566%6 6%6366%6 6%6)16366%6 6%6!66

Plot [ C4H9Cl ] versus time


01

2 1 R ti R t




C4H9Cl(aq)+ H2O(l) → C4H9OH(aq)+HCl (aq)

02

2 1 R ti R t



"(erage rate of disappearance of C>5C$


C4H9Cl(aq)+ H2O(l) → C4H9OH(aq)+HCl (aq)

03

[ ] [ ]( ) ( )

−−−=

−=

timeinitialtime#nalCl3CCl3C

t

Cl)3(C

timeinitial4/time#nal4/

4/

Δ

Δ

2 1 R ti R t



Time (s) [ C4H9Cl ](M) Ave.rate (M/s)

6%6 6%06666%6 6%656

066%6 6%63!606%6 6%620!66%6 6%6120)66%6 6%65

66%6 6%6366%6 6%6)16366%6 6%6!66

1*4 x 1-$/

1*. x 1-$/

1* x1-$/

1*/x1-$/

1*00x1-$/

1*-1 x1-$/

-*5-x1-$/

-*6x1-$/

2.1 Reactin RateE!pressinC4H9Cl(aq)+ H2O(l) → C4H9OH(aq)+HCl (aq)

05

Reactin Rates an&



Reactin ' relatinship ne)t)ne

C/34Cl (a7) 8 309 (l) C/3493 (a7) 8 3Cl

(a7)

1 mole of C/3493 is produced for each mole of

C/34Cl consumed* 309 is consumed and 3Cl is

produced*

Rate "

Reactin Rates an&Stichimetr*

!6

[ ] [ ]

[ ] [ ]

t

933C

t

Cl3C

t

3Cl

t

93

4/4/

0

Δ

Δ

Δ

Δ

Δ

Δ

Δ

Δ

=−

=−

Reactin Rates an&



Reatio! " relatio!s#i$ is !ot o!e%to o!e

!>I 9g >! 9g ? I!9g

The rate of disappearance of >I is twice the rate of

appearance of >! and I! %

rate ;

&! 'e!eral or" aA + *→

C + ,

rate ;


!0

[ ] [ ] [ ] [ ]

Δt

DΔ

d

1

Δt

CΔ

c

1

Δt

BΔ

b

1

Δt

AΔ

a

1==−=−

[ ] [ ] [ ]t

:

t

3

t

3:

0

1 00

Δ

Δ

Δ

Δ

Δ

Δ==−



!!

E!ample:

+rite the rate expressions for the fo$$owing

reactions in terms of the disappearance ofthe reactants and the appearance of the

prodcts%

@>) 9g ? O! 9g @O 9g ? 1>!O 9g




!)

Sl%tin'


[ ] [ ] [ ]

[ ]Δt

OHΔ

6

1

Δt NOΔ

41

ΔtOΔ

1

Δt NHΔ

41!ate

2

2"

=

=−=−=



!C>069g ? 0)O!9g 3CO!9g ? 06>!O9g

If the #tane concentration is decreasing at a

rate of 6%!6 mo$ L /0 s /0, at what rate is theox&gen concentration decreasingA

So$tion:

0%) mo$ O!rate 9O! ;6%!6 mo$ C>06

L s ! mo$ C>06

0) mo$ O!xL s

;

–

Ox&gen reacts at a rate of 0%) mo$ L /0 s /0


E!ample :

!



2.2 +actrs A,ectin# ReactinRate

Pri!i$al ators i!lue!e reatio! rates"0% Chemica$ natre of the reactants

!% "#i$it& of the reactants to come in contact with

each others

)% Concentrations of the reactants% Temperatre

% "(ai$a#i$it& of rate-acce$erating agents ca$$ed

cata$&sts

!



•C#emial !ature o t#e reata!ts – *ring reactions, #onds #rea. and new

#onds form

– Some reactions are fast #& natre and

others are s$ow


!1



• Ailit- o t#e reata!ts to meet

– Bost reactions in(o$(e two or more reactants

whose partic$es 9atoms, ions or mo$ec$es

mst co$$ide for the reaction to occr

– In a homogeneos reaction, a$$ of the reactants

are in the same phase

– In a heterogeneos reaction, the reactants are

present in different phases

urae area Rate


!2

2 2 +actrs A,ectin# Reactin



– The area of contact #etween the phases

determines the reaction rate

2.2 +actrs A,ectin# ReactinRate urae area

!3



": nai$ 9$ow srface area 4: Stee$ woo$ 9high srface area!5



• Co!e!tratio! o t#e reata!ts – The rates of #oth homogeneos and

heterogeneos reactions are affected #& the

concentrations of the reactantsFor examp$e, red-hot stee$ woo$ #rsts into f$ame

when thrst into pre ox&gen

Rate ∝ co$$ision fre'enc& ∝ concentration

Co!! Rate


)6



• Tem$erature o t#e s-stem – "$most a$$ chemica$ reactions occr

faster at higher temperatres

Rate ∝ co$$ision energ& ∝ temperatre

Tem$erature rate

a: energetic collision $ lead toproduct

b,c,d: molecules just bounce o;<<


)0



• Prese!e o atal-sts

– Cata$&sts are s#stances that increase

the rate of chemica$ reactions withot

#eing sed p

– For examp$e, enD&mes that direct or

#od& chemistr& are a$$ cata$&sts


)!

2 2 +actrs A,ectin# Reactin




• Prese!e o atal-sts

))



2.- Rate Las

• " rate $aw is an e'ation in which the rate is

gi(en as a fnction of reactant concentrations – for examp$e, rate ; k [H&]n

k is the rate constant of the reaction

n is the order of the reactant

4oth rate constant and order mst #eexperimenta$$& determined

)



2.- Rate Las

• The (a$e of the rate constant, . depends

on the partic$ar reaction #eing stdied

and the temperatre at which the

reaction occrs

• The order, n can #e positi(e or negati(e,

an integer or a fraction

• The order cannot #e dedced from the

#a$anced e'ation

)



2.- Rate Las

•T-$es o rate la0s"

– " differentia$ rate $aw expresses the rate as a

fnction of concentration

– "n integrated rate $aw expresses the

concentration as a fnction of time

)1

rate ; d7"8dt

; k 7"8

kt

t

e A Akt A

A −== 0t0 #$#$o!#$

#$ln



2.- Rate Las• Consider the h&pothetica$ reaction:

" ? 4 prodcts

The rate $aw for the reaction is:

rate ; k 7"8m748n

The (a$es of m and n can #e disco(ered #&

$oo.ing for patterns in the rate data 9experimenta$

data

Order cannot #e dedced from the #a$anced

e'ation)2



• Consider the fo$$owing reaction:

From experiment, the rate la0

9determined from initia$ rates is

Rate la0 a!!ot e otai!e rom t#e ala!e

equatio! 11111111

2.- Rate Las

)3

O H I Se H I SeO H 2""2

"246 ++→++ −+−

2"1

"2 #$#$#$!ate +−

= H I SeO H k



2.- Rate Las

Sppose that the data in the ta#$e #e$ow has

#een o#tained in a series of fi(e experiments:

" ? 4 prodct 9C

)5

2 - R t L



2.- Rate Las

– For experiments 0, ! and ) 748 is he$d constant% "n&

changes in the rate mst #e de to the change in 7"8

– The rate $aw sa&s that at constant 748 the rate mst

#e proportiona$ to 7"8m

rateexp 0

rateexp !;

7"8exp 0

7"8exp !m

rateexp 0

rateexp !;

6%6 mo$ L-0 s-0

6%!6 mo$ L-0 s-0; !

and

7"8exp 0

7"8exp !;

6%!6 mo$ L-0

6%06 mo$ L-0; !

" ? 4 prodct 9C

6



2.- Rate Las

– So do#$ing 7"8 from experiment 0 to experiment !

do#$es the rate

– The re$ationship redces to:

!%6 ; !%6m

– The on$& (a$e of n that ma.es this e'ation tre is

m ; 0

– The reaction mst #e first order with respect to "

" ? 4 prodct 9C

0



2.- Rate las

– In the fina$ three experiments, the concentration

of 4 changes whi$e the concentration of " is he$d

constant

–

This time it is 748 that affects the rate

– For experiments ) and , we ha(e:

%6 ; !%6n

–

Therefore,n

mst e'a$ !

rateexp )

rateexp ;

748exp )

748exp

n

" ? 4 prodct 9C

!



2.- Rate Las

– +e now .now that the rate $aw for the

reaction mst #e:

rate ; k 7"80748!

– The o(era$$ order is the sm of the orders for

each reactant in the rate $aw ; )

– +hat is the (a$e of k A

" ? 4 prodct 9C

)

2 / Inte#rate& Rate



2./ Inte#rate& RateLas• T#e i!te'rate rate la0s

– Integrated rate $aws express concentration as a

fnction of time

– Consider the h&pothetica$ reaction:

" prodcts

– The 9differentia$ rate $aw has the form:

rate 3[A]

t k [A]!

2 / Inte#rate& Rate



2./ Inte#rate& Ratelas

• ero%orer rate la0s !5

– The differentia$ rate $aw is:

rate ; k 7C86 ; k 90 ; k

– The integrated rate $aw is:

7C8t ; /kt

? 7C86

– " p$ot of 7C8 (erss time gi(es a straight

$ine of s$ope /k

2 / Inte#rate& Rate



1

2./ Inte#rate& Ratelas

ero%orer rate la0s



2./ Inte#rate& Rate Las

6irst%orer reatio!sAssume A $routs is irst orer !7

The differentia$ rate $aw has the form:

rate ; − d7"8dt

; k 7"8

The integrated rate $aw wo$d #e:

7 A86 is 7 A8 at t 9time ; 6

7 A8t is 7 A8 at t ; t

e = #ase of natra$ $ogarithms = 2.71828…2

kt

t

e A Akt A

A −

== 0t0

#$#$o!#$

#$ln



7"8t

7"86; kt $n 7"86e

-.t7"8t ;or

rate ; /d7"8

dt

; k 7"8

6irst%orer reatio!s

2./ Inte#rate& Rate Las

3

[ ][ ][ ]

[ ]

[ ] [ ] t% AlnAln

dt% A

Ad

0t

t

0

A

A

t

0

−=−

−= ∫ ∫

[ ] [ ] 0t Alnt% Aln +−=

2 / Inte#rate& Rate



5

2./ Inte#rate& RateLas – 6or irst orer reatio!s a p$ot of the natra$

$ogarithm of concentration (erss reaction timea$wa&s gi(es a straight $ine

2 / Inte#rate& Rate



6

The specific rate constant for the first-orderdecomposition of @!O in CC$ at oC is 1%)! ×06- s-0

!@!O @O! ? O!

a% +hat is the concentration of @!O remaining after

!%66 hr if the initia$ concentration of @!O was6%66 B A

#% >ow mch time re'ired for 56 of @!O to

decompose A

2./ Inte#rate& RateLas

E!ample

2 / Inte#rate& Rate



0

a% need a re$ationship #etween time and concentration

$n 7 " 8t ; -.t ? $n 7 " 8o , $n 7@!O8t ; -.t ? $n 7@!O8o

$n 7@!O8t ; -9 1%)! × 06- s-0 x

9!%66 hr × )166 s0 hr ? $n 96%66

$n 7@!O8t ; -% ? 9 -6%15) ; -%!

7@!O8t ; exp 9-%! ; %) × 06-)

B


Sl%tin

2./ Inte#rate& Rate



!

#% assme the fina$ concentration is 06 of the initia$concentration%

56 of @!O has decomposed, so on$& 06 remains

7@!O8 ; 96%096%66 B @!O; 6%666 B @!O

$n 7 6%666 8 ; - 91%)! × 06- s-0 t ? $n 7 6%66 8

- !%551 ; - 9 1%5) × 06-

s-0

t ? 9-6%15) t ; )%1 × 06) s

The time it ta.es for 56 of @!O to disappear is)16 s or 0%60 hrs


Sl%tin

2 / Inte#rate& Rate



)


• eo!%orer reatio!s !2

– "ssme 4 prodcts is second order

– The differentia$ rate $aw is:

– The integrated rate $aw wo$d #e:

rate [*]

t k [*]2

[*]5

7 k t +

[*]t

7

2./ Inte#rate& Rate



2./ Inte#rate& RateLas•

eo!%orer reatio!s

[ ][ ]

[ ][ ]

[ ][ ][ ]

[ ]

[ ] [ ] [ ] [ ]00

022

2

11&

11

&0

Bkt Bkt B B

dt k B

Bd t k

B

B

Bk t

B Rate

t t

A

A

t t

+==−

=−∆×−=∆

=∆

∆−=

∫ ∫

2./ Inte#rate& Rate




– +hen a reaction is seo! orer , a p$ot of 0748t

(erss t sho$d &ie$d a straight $ine with a s$ope k



1

0al lie

The amont of time re'ired for ha$f of areactant to disappear is ca$$ed the ha$f-$ife, t

1/2

– T#e #al%lie o a irst%orer reaction is not

affected #& the initia$ concentration

k t kt

A

A

A At t

kt A

A

t

t

2lno!

#$

#$ln

n'sbstitti &#$21#$&at

#$

#$ln la*!ateo!de!-+i!st

2/12/1

02

1

0

02/1

0

==

==

=

0 l li



2

First-order radioactive decay of iodine-131. The

initial concentration is represented by [I]0.

0al lie

0 l li



3

–T#e #al%lie o a seo!%orer reactionsdoes depend on the initia$ concentration

0al lie

0

2/12/1

0

2/1

002

1

02/1

0t

#$

lo!

#$

1

#$

1

#$

1

n's(bstit(ti &#$2

1#$&at

#$

1-

#$

1 )la*!ateinte'!atedo!de!-,econd

Bk t kt

B

kt B B

B Bt t

kt

B B

t

==

=

==

=



5

SUMMAR



E!ampleCarbon$1/ (1/C) is a radioactive isotopewith a half$life of 6*.2 x 1-2 years* t

decays following the #rst order reaction* he amount of 1/C present in an object canbe used to determined its age* Calculatethe rate constant for decay of 1/C and

determine how long is re7uired for 4-= ofthe 1/C in a sample to decompose*

16



2 3 Ther* chemical



2.3 Ther* chemical4inetics

• Co$$ision theor&

– One of the simp$est mode$s to exp$ain

reaction rates is co$$ision theor&

– Co$$ision theor& sa&s that the rate of a

reaction is proportiona$ to the nm#er of

effecti(e co$$isions per second among the

reactant mo$ec$es

– "n effecti(e co$$ision is one that acta$$&

gi(es prodct mo$ec$es

2 3 Ther* chemical




– Concentration can inf$ence the nm#er of

effecti(e co$$isions per second

– "s reactant concentrations increase, the

nm#er of effecti(e co$$isions increases – @ot e(er& co$$ision #etween reactant

mo$ec$es acta$$& res$ts in a chemica$

change

– On$& a (er& sma$$ fraction of a$$ the co$$isions

can rea$$& $ead to a net change

– +h& is this soA

2 3 Ther* chemical




• Bo$ec$ar orientation – +hen two reactant mo$ec$es co$$ide the& mst

#e oriented correct$& for a reaction to occr

9see next s$ide

2./ Ther* chemical



*4inetics

2 3 Ther* chemical




• Ativatio! e!er'-

– The acti(ation energ& 9Ea is the minimm

energ& re'ired for a reaction to occr

– The acti(ation energ& determines the rate of

a reaction

–

"t a gi(en temperatre, on$& a certain fractionof the co$$isions possess enogh energ& to #e

effecti(e and form prodcts

11

2 3 Ther* chemical




12

2 3 Ther* chemical




– The arrangement fond on the top of the

potentia$ energ& Ghi$$H is ca$$ed the acti(ated

comp$ex or transition state

– Once the transition state is reached, thereaction proceeds to gi(e prodcts, with the

re$ease of energ&

–

" reaction intermediate corresponds to anenerg& minimm #etween two transition

states

13

Transitin State



The acti(ated comp$ex is nsta#$e species and what exists

is neither reactant nor prodct #t a transitiona$ species

with partia$ #onds% Consider reaction #etween:

C>)4r ? O>- C>)O> ? 4r -

Transitin StateTher*

15

2./ Ther* chemical



*4inetics

• Tem$erature eets

– The rate of a reaction increases with increasingtemperatre

26

2./ Ther* chemical



2./ Ther* chemical4inetics

–

The acti(ation energ& is re$ated to the rateconstant #& the "rrhenis e'ation

k ; "e-EaRT

k ; rate constant

Ea ; acti(ation energ&

R ; ni(ersa$ gas constantT ; temperatre 9in e$(in

" ; pre-exponentia$ or fre'enc& factor 20

2./ Ther* chemical



2./ Ther* chemical4inetics

– The acti(ation energ& can a$so #e o#tained

from two rate components measred at

different temperatres

–

Bost reactions o#e& the "rrhenis e'ationto a good approximation

/$n

k !

k 0; R

/Ea 0

T!

0

T0

2!

E!ample



"n a$teration in the strctre of a certain (irs fo$$ows first-

order .inetics with Ea ; 32 .Jmo$ %The ha$f-$ife at !5%1oC is

0%1! × 06 s 9 0 &r ; )%0 × 062 s % +hat are the rate

constants at !5%1oC and the ha$f-$ife at )!oC for the a$teration

of the (irs A

olutio!

For a first order rxn: .0 ; 6%15) t0!

Rate constant at !5%1oC ; 6%15) 90%1! × 06 s

; %!3 × 06- s-0

E!ample

2)



Ea is gi(en, so .! can #e ca$c$ated sing the "rrhenise'ation%The t 0! at )!%6oC can #e o#tained from .!%

Sl%tin 5cnt.6

21-4-

2

2

1--

21

a

2

1

s10 2.6 %

"02.6

1

"0.0

1

/mol. ."14

/%)00%/mol)(10(

%

s104.2ln

3

1

3

1

5

%

%

ln

×=

−×

=

×

−−=



Sl%tin 5cnt.6

2

s1-0*65

s 1-0*5

-*42

?%-*42 t

:C20atlife$half thethus

2

1$/

01%0

o

×=

×

=

=

−

2.7 Reactin



2.7 Reactinmechanisms

• Bost reactions do not occr in a sing$e

step

• The net o(era$$ reaction is the res$t of a

series of simp$e reactions

• Each of these is ca$$ed an e$ementar&

process

• The entire set of e$ementar& processes is

the reaction mechanism

21

2.7 Reactin



2.7 Reactinmechanisms

• The rate $aw of an e$ementar& process can

#e written from its chemica$ e'ation

• This r$e on$& app$ies to e$ementar&

processes

• T#e overall rate la0 erive rom t#e

me#a!ism must a'ree 0it# t#e

oserve rate la0 or t#e overall

reatio!

22

E l



The fo$$owing two reactions are proposed as e$ementar& steps in the

mechanism for an o(era$$ reaction:

90 @O!C$ 9g @O! 9g ? C$ 9g

9! @O!C$9g ? C$ 9g @O!9g ? C$!9g

O(era$$ reaction: 90 ? 9!

O(era$$ rxn: !@O!C$9g!@O! 9g ? C$!

Reaction intermediate is a s#stance that is formed and sed p inthe o(era$$ reaction, does not appear in the o(era$$ reaction: C$ 9g

Rxn90 : Knimo$ec$ar, Rate ; .07@O!C$8

Rxn9!: 4imo$ec$ar, Rate ; .!7@O!C$87C$8

E!ample

23

2.7 Reactin



7 eac mechanisms

• The rate-determining step – Consider the gaseos reaction:

!@O!C$ !@O! ? C$!

– The acta$ mechanism of the reaction is the

fo$$owing two-step se'ence of e$ementar&

processes:

@O!C$ @O! ? C$ 9s$ow@O!C$ ? C$ @O! ? C$! 9fast

– The C$ radica$ formed is an intermediate25

2.7 Reactin



mechanisms

• In an& m$tistep mechanism, one step is

sa$$& mch s$ower than the others

• The s$ow step in a mechanism is ca$$ed

the rate-determining step

• The rate la0 or t#e rate%etermi!i!'

ste$ is iretl- relate to t#e rate la0or t#e overall reatio!

36

2.3 Reactin



• The rate $imiting step wi$$ dominate the

expression of rate $aws%

Eg:

Step 0: @O 9g ? 4r ! 9g @O4r ! 9fast

Step !: @O4r ! 9g ? @O 9g !@O4r 9g 9s$ow

∴Rate $aw : Rate;.7@O4r !8 7@O8

Rate laws for elementarysteps

mechanisms

30

E l



@9 catalyAes the decomposition of @09 possiblythrough the following mechanism:

@9(g) 8 @09(g) → @

0(g) 8 @9

0(g)

0@90(g) → 0@9(g) 8 9

0(g)

>hat is the overall reactionB

516 × 2 2NO 5#6 8 2N2O 5#6 → 2N2 5#6 8 2NO2

5#6

526 2NO25#6→

2NO5#6 8 O25#6999999999999999999999999999999999 2N

2O 5#6 → 2N2 5#6 8O

25#6

NO = catalyst;NO2=intermediate

E!ample

3!



T#e 8!

Chapter 2 Chemical Kinetics

Documents