dosageahnaoh

8/18/2019 DosageAHNaOH

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TITRAGE pH-METRIQUE D'UN ACIDE FAIBLE PAR UNE BASE FORTE

pH-mètre

4,8

AH ! C",#",p$"

N"OH ! C% & #%

O (t)*+e e t+tr"e *') ".+*e /"+%e AH p"r )e %"0e /

N1)0 "10 (t"%+r e0 (5)"t+10 *1"t " .1)r%e *epH 6 / 2R3R e0t e r"pp1rt *e t+tr"e *(/++ p"r R 6 C% #% 7 C" #"P1)r #% 6 669 R 6 P1)r C% #% : C" #" 669 R : ; 1 e0t "1*e0 et (t"%+r10 "+0+ +err Br+ere


2/28

1rte 2N"OH3

t+tr"e !

+è0e 5)e "t tre .10+*(r(e

0 *1m"+e0 *e

ppr1=+m"t+10

e ."0 *e0 ".+*e0

)t++0"t ) +*+."te)re p"r ) m"=+m)mr " p10+t+1 *) p1+t

EURS

RETOUR ACCUEIL


3/28

Résolution exacte du problème

N1)0 "10 p1)r 0+mp+/+er e pr1%ème et e r"meer ") prem+er *er( .10+*(rer 5)e '+1 e pHLe0 e0pè.e0 pr(0ete0 e 01)t+1 01t ! AH & A - & H

O & OH- & N"

D(/++t+1 *) $" ! $" 6 A- HO 7 AHEe.tr1e)tr"+t( ! H

O N" 6 A- OH-

C10er


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.1)e e0t e r"pp1rt *e t+tr"t+1 R et

1rme0

".)er e0


5/28

Résolution approximative du problème

N1)0 "10 m"+te"t (t"%+r )e r(01)t+1 %e").1)p p)0 0+mpe *) pr1%ème m1"ppr1=+m"t+10O 0)pp10e 5)e " 0e)e r(".t+1 5)+ 0e pr1*)+t ") .1)r0 *) t+tr"e e0

/"+%e AH p"r '+1 H*r1=*e OH -R(".t+1 *e t+tr"e ! AH OH- 6 A- H

O

C10t"te *'(5)++%re ! $R 6 A- 7 2 OH- AH 3

M)+p+10 *(1m+"te)r et )m(r"te)r p"r HO

$R 6 A- H

O 7 2 OH- AH H

O 3 6 $" 7 $e

P1)r /+=er e0 .>10e0 0)pp1010 5)e '".+*e *10( e 01+t + tr1p /"+%e 2p$" : ;3 + tr1" .10t"te $

R e0t "1r0 .1mpr+0e etre ;-; 7;-;4 6 ;4 et ;- 7;-;46;;;

L"


6/28

)" 6 e erme - 0 ") e e 1 e pe) 1. ." .) er e p

I re0te *e)= ."0 p"rt+.)+er ? (t)*+er !S1)t+1 ++t+"e 5)"* R 6 P1+t E5)+


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"t .ert"+e0" e)tr"+0"t+1 *e '".+*e

p /1rt 2p$" : 3 "


8/28

)e ."00+5)e

e pH e0t *1( p"r "


9/28

COMPARAISON DES RES!"A"S E#AC"S E" APRO#IMA"I$S

;3 C>1+0+r e0 p"r"mètre0

3 C+5)e 0)r CALCULS

Cb 0.1 10Ca 0.1 10

Va 10 10

pKa 4 40

Ka 0.0001

R pH H K M R R pH #r"+ pH "ppr1= R

0 2.5069 0.0031 3E-012 0.0311 0 0 2.506867 2.5 0

0.1 3.0875 0.0008 1E-011 0.109 ### 0.1 3.087515 3.045757 0.1 0.0417580.2 3.4105 0.0004 3E-011 0.2047 ### 0.2 3.410489 3.39794 0.2 0.012549

0.3 3.6382 0.0002 4E-011 0.303 ### 0.3 3.63819 3.632023 0.3 0.006167

0.4 3.8277 0.0001 7E-011 0.4021 ### 0.4 3.827673 3.823909 0.4 0.003764

0.5 4.0026 1E-004 1E-010 0.5015 ### 0.5 4.00259 4 0.5 0.00259

0.6 4.178 7E-005 2E-010 0.6011 ### 0.6 4.178014 4.176091 0.6 0.001923

0.7 4.3695 4E-005 2E-010 0.7007 ### 0.7 4.369479 4.367977 0.7 0.001503

0.8 4.6033 2E-005 4E-010 0.8004 ### 0.8 4.603279 4.60206 0.8 0.001219

0.9 4.9553 1E-005 9E-010 0.9002 ### 0.9 4.95526 4.954243 0.9 0.001017

1 8.3499 4E-009 2E-006 1 ### 1 8.349909 8.349485 1

1.1 11.678 2E-012 0.0048 1 ### 1.1 11.67778 11.67778 1.1 9.1E-008

1.2 11.959 1E-012 0.0091 1 ### 1.2 11.95861 11.95861 1.2 2.4E-0081.3 12.115 8E-013 0.013 1 ### 1.3 12.11539 12.11539 1.3 1.1E-008

1.4 12.222 6E-013 0.0167 1 ### 1.4 12.22185 12.22185 1.4 6.5E-009

1.5 12.301 5E-013 0.02 1 ### 1.5 12.30103 12.30103 1.5 4.4E-009

pH

@

;

;@

@

@

4

4@

E.

0 0.2 0.4 0.6 0.8 1 1.2 1.4

0

2

4

6

810

12

14

pH Vrai pH approx

4

6

8

10

12

14

Ar"*+r


10/28

0 0.2 0.4 0.6 0.8

0

2

pH Vrai pH approx

4 8

@

;

;@

@

C

C@

4

4@

E."rt pH

R


11/28

Pr(.+0+1 0)r pH

; @ ;

OUI OUI OUIOUI OUI OUI

OUI OUI OUI

OUI OUI OUI

OUI OUI OUI

OUI OUI OUI

OUI OUI OUI

OUI OUI OUI

OUI OUI OUI

OUI OUI OUI

OUI OUI OUIOUI OUI OUI

OUI OUI OUI

OUI OUI OUI

4 8 ; ; ;4

rt pH

R

RETOUR

Ar"*+r


12/28

1 1.2 1.4

; ; ;4

RETOR


13/28

NE PREMIERE ANA!%SE DES RES!"A"S O&"ENS'

L')t++0"t+1 *e " /e)+e pr(.(*"te m1tre 5)e e0 r(0)t"t0 1%te)0 p"r " m(t>1*e "e ."0 ((r" t1)t ? /"+t .1rre.t0N1)0 "10 re"r*er .e" *e p)0 prè0 !

P1)r


14/28

L'erre)r re0te ("m1+0 t1)1)r0 (+e"%

E."rt pH

-,

,

,4

,

,8

,;

,@ ; ;,@

R

43 8 : p$" : ;

D"0 .e ."0 *e /+)re 1 1%0er


15/28


16/28

pr1=+m"t+


17/28

e

rè0 %1 "..1r* etre)t ") 1 *) t+tr"eR e0t t1)te/1+00e) m"=+m)m 0+t)(

e


18/28


19/28

C% 44 44

C" 7

#" 26

p$" 32

Ka 0.00063096

V! pH pHap " $H %$H

0 0.00 2.20 0.00633783 0.09054045 -1.712E-020

V&'(2 4.14 7.00 0.0000001 0.99984154 -6.999E-009

V&' 4.14 7.00 0.0000001 0.99984154 -6.999E-009

2V&' 8.27 12.73 1.883E-013 1 -2.318E-014

)a* 0.26317659

pH " $H %$H %+aOH V! pH

2.20 0.00633783 0.09054045 -1.712E-020 0.00282881 1.573E-016 2.19805929

2.46 0.00345752 0.15432593 -2.540E-005 0.00153326 0.43065632 2.46123587

2.72 0.0018862 0.25066274 -2.954E-005 0.00083349 0.92142505 2.72441246

2.99 0.00102899 0.38010695 -0.00002632 0.00045381 1.50793018 2.98758904

3.25 0.00056135 0.52918982 -2.048E-005 0.00024731 2.15300399 3.25076563

3.51 0.00030624 0.6732406 -1.434E-005 0.00013484 2.76474788 3.51394222

3.78 0.00016706 0.79065286 -9.218E-006 7.354E-005 3.25931827 3.77711884.04 9.114E-005 0.87378545 -5.566E-006 4.011E-005 3.60816151 4.04029539

4.30 4.972E-005 0.9269556 -3.224E-006 2.188E-005 3.83085457 4.30347197

4.57 2.712E-005 0.95878342 -1.820E-006 1.194E-005 3.96402976 4.56664856

4.83 1.480E-005 0.97708565 -1.012E-006 6.511E-006 4.04057136 4.82982515

5.09 8.072E-006 0.98736785 -5.579E-007 3.552E-006 4.08356064 5.09300173

5.36 4.404E-006 0.99306892 -3.061E-007 1.938E-006 4.10739298 5.35617832

5.62 2.402E-006 0.9962069 -1.675E-007 1.057E-006 4.12050981 5.6193549

5.88 1.311E-006 0.99792715 -9.155E-008 5.767E-007 4.12770037 5.88253149

6.15 7.150E-007 0.99886812 -0.00000005 3.146E-007 4.13163377 6.14570808

6.41 0.00000039 0.9993822 -2.729E-008 1.716E-007 4.13378324 6.40888466

6.67 2.128E-007 0.99966287 -1.489E-008 9.362E-008 4.13495781 6.67206125

6.94 1.161E-007 0.99981606 -8.124E-009 5.108E-008 4.13560073 6.935237837.20 6.333E-008 0.99989964 -4.432E-009 2.786E-008 4.13595501 7.19841442

Be) *e Br1m1t>m1 2 , -

-éliant.ine / 012 3

P.énolp.talé6ne / 7 3

0 1 2 3 4 5

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14


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7.46 3.455E-008 0.99994525 -2.418E-009 1.520E-008 4.13615463 7.46159101

7.72 1.885E-008 0.99997013 -1.319E-009 8.292E-009 4.13627514 7.72476759

7.99 1.028E-008 0.99998371 -7.197E-010 4.524E-009 4.13636215 7.98794418

8.25 5.609E-009 0.99999111 -3.926E-010 2.468E-009 4.13644859 8.25112076

8.51 3.060E-009 0.99999515 -2.142E-010 1.346E-009 4.13656721 8.51429735

8.78 1.669E-009 0.99999735 -1.169E-010 7.345E-010 4.13676289 8.77747393

9.04 9.106E-010 0.99999856 -6.376E-011 4.007E-010 4.13710975 9.04065052

9.30 4.968E-010 0.99999921 -3.479E-011 2.186E-010 4.13773909 9.30382711

9.57 2.710E-010 0.99999957 -1.898E-011 1.192E-010 4.13888927 9.56700369

9.83 1.478E-010 0.99999977 -1.036E-011 6.504E-011 4.1409959 9.83018028

10.09 8.066E-011 0.99999987 -5.656E-012 3.548E-011 4.1448572 10.0933569

10.36 4.400E-011 0.99999993 -3.090E-012 1.935E-011 4.1519372 10.3565335

10.62 2.400E-011 0.99999996 -1.690E-012 1.055E-011 4.16492357 10.61971

10.88 1.310E-011 0.99999998 -9.267E-013 5.752E-012 4.18875726 10.8828866

11.15 7.144E-012 0.99999999 -5.101E-013 3.133E-012 4.23254369 11.1460632

11.41 3.897E-012 0.99999999 -2.828E-013 1.705E-012 4.31313745 11.4092398

11.67 2.126E-012 1 -1.588E-013 9.255E-013 4.46199182 11.6724164

11.94 1.160E-012 1 -9.119E-014 5.003E-013 4.73868118 11.93559312.20 6.327E-013 1 -5.429E-014 2.684E-013 5.25914171 12.1987696

12.46 3.452E-013 1 -3.416E-014 1.419E-013 6.2604066 12.4619461

12.73 1.883E-013 1 -2.318E-014 7.286E-014 8.27272727 12.7251227


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1

%+aOH ,V Vrai

0.00282881 0.00015732 0

4.400E-008 2067526353 2.06818182

4.400E-008 -655465.573 4.13636364

7.286E-014 0 8.27272727

0

/ri/&

0 0.61110582

0 0.53625378

0 0.44872001

0 0.40797903

0 0.43020713

0 0.532131710 0.75442651

0 1.1817907

0 1.97616821

0 3.4383473

0 6.12191145

0 11.0428324

0 20.0640452

0 36.6002969

0 66.9081811

0 122.437792

0 224.062817

0 409.3413920 742.861222

, 3

14 5

8 5

6 7 8 9


22/28

0 1318.37232

0 2183.872

0 3024.70208

0 3044.36582

0 2218.78279

0 1344.88832

0 758.759538

0 418.172868

0 228.81502

0 124.927456

0 68.1574771

0 37.1718758

0 20.2655952

0 11.0422068

0 6.01046067

0 3.26547074

0 1.76801394

0 0.951162640 0.50566099

0 0.26284412

0 0.13078263


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C% 4 34

Amélioration de l*approximation pour des acides relativement (orts de p9a

N1)0 " 2 % > 3 7 2 " - % - > 3"$" - %$" - $" > 6 > % > > 2% $"3 > - 2 " - % 3 $" 6 L" r(01)t+1 *e .ette (5)"t+1 *) 0e.1* *er( permetr" *e .".)er e pH e /1.t+1 *e" 6 C" 7 2;RO3% 6 R " 6 R C" 7 2;RO3" - % 6 C" 7 2;RO3 - R C" 7 2;RO3 6 C" 2 ; - R 3 7 2;RO3> 2R C" 7 2;RO33 $"3J > - C" $" 2 ; - R 3 7 2;RO3 6

6 2R C" 7 2;RO33 $"3J 4 $" C" 2 ; - R 3 7 2; RO 3

> 6 - ;7 2R C" 7 2;RO33 $"3J 2 2R C" 7 2;RO33 - $"3J 4 $" C" 2 ; - R 3 7 2; RO 33 ;7

Se)e .ette r".+e e0t p10+t+

-

CE-;

4E-;

Ear! pH

@

C

C@

H a

AGRANDIR


24/28

C" 37

p$" @ 253

$" @E-

R pH H K M R R χ > R pH "p

; ;; ;; 4 ; -; 4 4@8 ;; ;88 ;@ ; ;4 4 -; @ ;@ ;4 ;88

; ; @ @ -; ; 48 ;

4 ;8 ; 8@ -; @ ; ;8

@ @ 4 8 ; ;4 4 8; @

@; 4@ 48 ; ;@8 48 @;

; @ ; ; @

8 8 ; ; ; ;@ ; ;@ 8

88 ; 8@; 84 ; -E-@ ; 848 88

; C

;E-;

; C 4 @ P 8 T

@

;

pH -rai

O


25/28

; 4 @

@E-;;

;E-;

;@E-;

E-;

@E-;

RETORE

TOR


26/28

: 01;

*(met *1e *e0

"prè0 e P1+t

e /"+%e AH p"r '+1 OH -

+ e p$" *e '".+*e

+%e

*'(e.tr1e)tr"+t(

et % et *1. *e R


27/28

pH


28/28

8

dosageahnaoh

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