SOLUBILITE / PRECIPITATION - univ.ency …univ.ency-education.com/.../1/0/13102001/pharm2an16_ch_anal-solubil… · Introduction Sels peu soluble ... B- Influence de l’environnement

SOLUBILITE

PRECIPITATION

2egraveme Anneacutee de Pharmacie

Deacutecembre 2015

Mr A BOUDIS

Laboratoire de Chimie Analytique

ETUDE DES SELS PEU SOLUBLES

A- Consideacuterations geacuteneacuterales

A-1-Deacutefinition de la solubiliteacute

La solubiliteacute laquo S raquo est deacutefinie comme eacutetant

quantiteacute maximale de corps que lrsquoon peut dissoudre

dans un volume deacutetermineacute du solvant liquide

Lorsque cette quantiteacute normale est

atteinte la solution est satureacutee et lorsque

cette quantiteacute est deacutepasseacutee on dit qursquoil y a

preacutecipitation du soluteacute

Introduction

Sels peu soluble Equilibres en solution heacuteteacuterogegravene

A-2- Diffeacuterentes cateacutegories drsquoun composeacute

La structure conditionne la solubiliteacute drsquoune

substance laquo Le semblable dissout le semblable raquo

Drsquoune faccedilon geacuteneacuterale un solvant polaire

peut dissoudre un soluteacute polaire et un solvant

apolaire dissoudra plus facilement un soluteacute

apolaire

Des composeacutes solubles

Des composeacutes insolubles

Des composeacutes peu solubles

En particulier les sels sont solubles dans des

solvants comme leau Cependant la solubiliteacute des

sels dans leau est extrecircmement variable

A-3 Expression de la solubiliteacute des composeacutes

peu solubles

A-3-1 Equilibre de dissolution-preacutecipitation

A une tempeacuterature donneacutee lorsqursquo on ajoute en

quantiteacute appreacuteciable du soluteacute au solvant on atteint la

limite de solubiliteacute pour le soluteacute consideacutereacute On obtient

au moins deux phases

Solution satureacutee

(MX M+ + X-)

Solide preacutecipiteacute de MX

Drsquoougrave

[MX] MX M+ + X-

Solide

dissous

Solide

solution

satureacutee

Expression geacuteneacuterale

[MnXm] [ MnXm] nMm+ + mXn-

[MnXm] composeacute en solution agrave lrsquoeacutetat moleacuteculaire en

concentration maximale

A-3-2 Le produit de solubiliteacute

Soit lrsquoeacutequilibre de dissociation drsquoun composeacute

MnXm en solution homogegravene

MnXm nMm+ + mXn-

bullApplicabiliteacute de la loi drsquoaction de masse

|Mm+|n |Xn-|m

|MnXm|

|MnXm| Concentration maximale du composeacute en

solution = S

KcS = |Mm+|n|Xn-|m = Ksp

Ksp est une constante pour une tempeacuterature donneacutee

Le produit de solubiliteacute est une constante qui permet de

-Deacutefinir la quantiteacute limiteacutee de substance dissoute

(solubiliteacute)

-Preacutevoir les conditions de formation drsquoun preacutecipiteacute

solide (preacutecipitation)

Ksp = |Mm+| |Xn-|

Si |Mm+| |Xn-| lt Ksp le corps reste dissous

Si |Mm+| |Xn-| gt Ksp il y a preacutecipitation sous forme

solide

Si |Mm+| |Xn-| = Ksp La solution est satureacutee 7

Tableau 1 Produit de solubiliteacute de quelques

composeacutes peu solubles

Sel Expression de kSP Valeur de KSp pKSp

AgCl KSP = [Ag+][Cl-] 1810-10 977

AgBr KSP = [Ag+][Br-] 510-13 143

AgI KSP = [Ag+][I-] 4510-17 1634

AgSCN KSP = [Ag+][SCN-] 10-12 12

Ag2CrO4 KSP = [Ag+]2[CrO4-2] 1310-12 1188

AgOH KSP = [Ag+][OH-] 210-8 739

Mg(OH)2 KSP = [Mg+2][OH-]2 510-12 113

BaSO4 KSP = [Ba+2][SO4-2] 1110-10 995

Pb3(PO4)2 KSP = [Pb+2]3[PO4-3]2 7910-43 421

Utilisation de la notion laquo p raquo

pKsp = npMm+ + mpXn-

pKsp = pM+ + pX- (pour m= n = 1)

laquo p raquo exprimant le cologarithme

Ksp est la valeur correspondant agrave la solution

satureacutee cest donc le produit ionique maximum

compatible avec labsence de preacutecipitation Pour

cette raison il est appeleacute produit de solubiliteacute

Relation entre Ksp et la solubilteacute

MmXn mMn+ + nXm-

S mS nS

| Mn+| = mS

|Xm-| = nS

Exemple AgCl Ag+ + Cl-

Cas geacuteneacuteral

soit un produit ApBq de solubiliteacute laquo S raquo

S = Concentration analytique de la solution satureacutee

Ksp = |Aq+|p |Bp-|q

La solution est satureacutee en ApBq donc la concentration

de la solution = S

ApBq pAq+ + qBp-

Concentrations ioniques

|Aq+| = pS |Bp-| = qS

Ksp = |pS|p |qS|q

= Sp+q ppqq

Sp+q = Ksp ppqq

p+q Ksp

Exemple 12

B- Influence de lrsquoenvironnement sur la

solubiliteacute

Comme tout eacutequilibre chimique lrsquoeacutequilibre entre un

sel solide et ses ions est dynamique et peut subir

des deacuteplacements sous diffeacuterentes influences

1- Influence de la tempeacuterature

2- Influence de lrsquoeacutetat physique du composeacute

3- Influence des solution drsquoeacutelectrolytes homo-ioniques

4- Influence des composeacutes heacuteteacuteroioniques

lrsquoeffet de la tempeacuterature deacutepend de lrsquoenthalpie de la

reacuteaction sel solide δH sel dissous

Si δH gt 0 La dissolution est favoriseacutee par lrsquoeacuteleacutevation

de la tempeacuterature laquo S raquo augmente

Si δH lt 0 La chaleur de dissolution est gt 0 donc

laquo S raquo diminue lorsque la Tdeg srsquoeacutelegraveve

Les diffeacuterentes formes polymorphes drsquoun compose

ont des solubiliteacutes diffeacuterentes

Ex Anhydride arseacutenieux

-Forme vitreuse S = 33 gL

-Forme cristalliseacutee S = 17 gL 14

3- Influence des solutions drsquoeacutelectrolytes homo-ioniques

laquo Solution homoionique solution contenant des

composeacutes solubles posseacutedant un ion commun

avec MnXm raquo

Ex NaCl est AgNO3 sont homoioniques au AgCl

a) Effet insolubilisant de la solution homoionique

AgCl Ag+ + Cl- 2

Si on introduit dans la solution de AgCl une substance

libeacuterant des ions Ag+ lrsquoeacutequilibre est deacuteplaceacute dans le sens

(2) Lrsquoaddition des Cl- provoquerait le mecircme effet

Influence dun excegraves de reacuteactif preacutecipitant

Il y a preacutecipitation de AgCl La solubiliteacute

diminue on dit qursquoil y a recul de solubiliteacute ou

encore effet drsquoion commun

Exemple Solution satureacutee de BaSO4

Ksp = 10-10

|Ba2+| |SO42-| = Ksp |Ba2+| = |SO4

2-| = Ksp = 105-

Si on ajoute dans cette solution du sulfate de sodium

SO4Na2 jusqursquoagrave obtenir de |SO42-| = 102-

nous avons tjs Ksp = |Ba2+| |SO42-| = 1010-

Apregraves addition de SO4Na2 nous aurons

|Ba2+| = 1010- 10 2-

|Ba2+| = 108-

On passe de 105- agrave 108- donc il y a diminution de

la solubiliteacute qui due agrave lrsquoeffet drsquoion commun

recul de solubiliteacute

Un leacuteger excegraves de reacuteactif preacutecipitant a donc

pour effet dameacuteliorer la preacutecipitation On dit

quil exerce un effet insolubilisant

b)- Effet dissolvant de la solution homoionoque

Possibiliteacute dun rocircle dissolvant dun large excegraves par

formation de complexes

AgCl + 2HCl H2 [AgCl3]

Complexe anionique

qui est soluble

Un grand excegraves de reacuteactif preacutecipitant peut donc

reacuteduire la preacutecipitation et exercer un effet de

redissolution

Influence de lrsquoenvironnement

4- Influence des solutions eacutelectrolytes heacuteteacutero-ioniques

Ce sont des solutions contenant des ions diffeacuterents de

ceux qui constituent le preacutecipiteacute Trois cas agrave envisager

a)- Lrsquoeacutelectrolyte heacuteteacutero-ionique est un un protolyte

b)- Lrsquoeacutelectrolyte heacuteteacuteroionique donne des ions

complexant ceux du composeacute peu soluble

c)- Leacutelectrolyte heacuteteacuteroionique donne des ions formant

avec ceux du composeacute peu soluble un autre composeacute

peu soluble

d)- Lrsquoeacutelectrolyte heacuteteacuteroionique est un sel quelconque

a)- Lrsquoeacutelectrolyte heacuteteacutero-ionique est un protolyte

Lrsquoeacutelectrolyte donne des ions susceptibles de reacuteagir avec

les anions ou les cations du composeacute peu soluble pour

avoir des reacuteactions acido-basiques

Si le protolyte est un acide

Il libegravere des protons dans la solution dans le cas ougrave le

sel est un sel drsquoacide plus faible que le protolyte llsquoanion

libeacutereacute manifeste des proprieacuteteacutes basiques et capte le H+

Il en reacutesulte une molarisation partielle drsquoougrave lrsquoaugmentation

de la solubiliteacute du sel

- Il est de mecircme si le protolyte est une base et dans le cas ougrave le sel

est un sel drsquoune base plus faible

Exemple solubiliteacute de AgNO2 en milieu acide

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

Acidification du milieu par HCl

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

Les NO2- proviennent de AgNO2

dissout et de HNO2 formeacute

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

De cette eacutequation on constate que la solubiliteacute varie avec

la [H+] c-agrave-d avec le pH si [H+] augmente le pH diminue et

S augmente

pH S en molariteacute

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

Tableau Solubiliteacute de AgNO2 dans lrsquoeau en fonction du

+ le pH

augmente

+ la solubiliteacute

diminue

- Un sel MB peu soluble est mis en preacutesence dun ligand L

Deux eacutequilibres sont en compeacutetition

i) La formation du sel MB deacutecrite par le Ksp

ii) La formation dun complexe MLn deacutecrite par n (Ks)

Exemple drsquoune solution de sel drsquoargent

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

On va ajouter en solution les NH3 il se forme avec Ag+

des complexes argentodiamines selon lrsquoeacutequilibre

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

Lrsquoaddition drsquoNH3

augmente

effectivement la

solubilteacute de AgCl

c)- Lrsquoeacutelectrolyte heacuteteacuteroionique donne des ions formant

peu soluble

- Un sel eacutelectrolyte augmente la solubiliteacute du composeacute

peu soluble degraves que sa concentration est suffisante

pour que le 2egraveme composeacute peu soluble preacutecipite

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

On ajoute un excegraves de KSCN qui donne avec Ag+

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

[SCN-] lt 08 10-7 AgSCN ne preacutecipite pas

[SCN-] = 08 10-7 commencement de preacutecipitation

[SCN-] gt 08 10-7 AgSCN preacutecipite

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

Limportance du pheacutenomegravene deacutepend de la concentration

en sel ajouteacute mais aussi surtout de la valeur de Ksp1 et

En effet si Ksp2 gt Ksp1 le deuxiegraveme composeacute

susceptible de preacutecipiter ne le fera que pour des

concentrations relativement grandes dans le cas

contraire il preacutecipite mecircme pour des tregraves faibles

concentrations

Un sel eacutelectrolyte intervient sur la solubiliteacute dans la

mesure ougrave sa concentration est suffisante pour que la

force ionique de la solution augmente notablement

Lrsquoexpression du Ksp srsquoeacutecrit en fonction des activiteacutes

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

A et B sont les coefficients drsquoactiviteacutes relatifs agrave A- et B+

Si A B = 1 Ksp = [A-][B+] aucune influence

Si A B lt 1 Ksp gt [A-][B+] S augmente

[A-][B+] = KSp A B

2egraveme partie du cours Solubiliteacute

C- Preacutecipitation fractionneacutee

C- Preacutecipitation fractionneacutee Si une solution contient plusieurs ions susceptibles de donner un preacutecipiteacute avec un mecircme antagoniste les sels ne vont pas se former en mecircme temps mais successivement en raison des diffeacuterences des produits de solubiliteacute

1 Les diffeacuterents ions preacutecipitant ont des charges identiques

Exemple la preacutecipitation des trois halogeacutenures dargent I- Br- et Cl- lorsquune solution de AgNO3 est ajouteacutee peu agrave peu agrave une solution contenant les trois anions agrave des concentrations voisines sachant que AgCl le Ksp = 18 10-10

AgBr le Ksp = 5 10-13

AgI le KSp = 45 10-17

Preacutecipitation fractionneacutee

[Ag+][I-] = 47 10-17

La concentration maximale en ion argentique compatible avec labsence de preacutecipitation peut ecirctre deacuteduite de la concentration en iodure

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

Degraves que cette valeur est deacutepasseacutee le AgI commence agrave preacutecipiter Si lon reporte cette valeur dans le produit de solubiliteacute du bromure dargent

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

Soit [Br-] asymp 104

Pour que le bromure dargent preacutecipite en mecircme temps que liodure il faudrait que la concentration en bromure soit 10000 plus forte que celle en iodure

Au fur et agrave mesure de la preacutecipitation [I-] et [Ag+] jusquagrave atteindre la valeur agrave partir de laquelle les bromures commencent agrave preacutecipiter

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

Le mecircme raisonnement appliqueacute aux chlorures montre pour que ceux-ci preacutecipitent au mecircme temps que les Br- il faut que

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Exemple Action dune solution de nitrate dargent sur une solution contenant un meacutelange de chromate et de chlorure

Ksp Ag2CrO4 = 13 10-12

Ksp AgCl = 18 10-10 Or cest le chlorure dargent qui preacutecipite en premier et non le chromate En effet

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

2 Les diffeacuterents ions preacutecipitant ont des charges diffeacuterentes

La simple comparaison des produits de solubiliteacute est insuffisante pour preacutevoir les reacuteactions

Donc pour une solution de chromate 001 N [Ag+] asymp 10-5

Pour une solution de chlorure de mecircme concentration [Ag+] = 18 10-8

Il faut donc une concentration beaucoup plus grande en ion argentique pour preacutecipiter le chromate que le chlorure

Cette observation est agrave la base de lemploi des chromates comme indicateur en argentomeacutetrie (meacutethode de Mohr)

D- Surcharge des preacutecipiteacutes

Locclusion reacutesulte de l emprisonnement par le preacutecipiteacute de sels preacutesents dans la solution Ce pheacutenomegravene peut se produire lorsque le preacutecipiteacute reacutesultant de leacutechange dions se forme trop rapidement

Ladsorption est une contamination qui se produit en surface du preacutecipiteacute de sels preacutesents dans la solution Qui peuvent ainsi sadsorber sur le preacutecipiteacute

Cependant ladsorption nest pas toujours une gecircne elle est mecircme utiliseacutee pratiquement pour permettre lindication du point deacutequivalence dans la meacutethode de Fajans

E- Applications analytiques

En Analyse qualitative Recherche des anions ou des cations dans une solution par lrsquoobservation drsquoune formation drsquoun preacutecipiteacute

En analyse Quantitative

- On peut doser un ion preacutesent dans une solution en lrsquoengageant dans un preacutecipiteacute qui est recueilli et peseacute crsquoest le but de lrsquoanalyse gravimeacutetrique

- On peut eacutegalement ajouter une solution titreacutee contenant lrsquoion provoquant la preacutecipitation on met ainsi en œuvre des meacutethodes titrimeacutetriques les plus utiliseacutees sont des meacutethodes argentimeacutetriques qui utilisent le pouvoir preacutecipitant de Ag+ vis-agrave-vis de diffeacuterents ions

Applications analytiques

- Etalons sont nombreux

1- Nitrate drsquoargent sel tregraves pur 999 PM = 16989 g stable

2- Argent meacutetallique PM = 10787g tregraves pur preacutepareacute dans lrsquoacide nitrique et lrsquoeau

3- Halogeacutenures NaCl KCl KBr KI helliphellip

- Les solutions titreacutees

1- Nitrate drsquoargent agrave 01 N

2- Solution de thiocyanate (KSCN NaSCN) 01 N

Meacutethode de Mohr - En milieu neutre Meacutethode de Fajans

E-2- Meacutethodes de dosage

- En milieu acide Meacutethode de Charpentier-Volhard

1 Argentomeacutetrie en milieu acide

- En opeacuterant en milieu acide fort (nitrique) on rend plus seacutelective la preacutecipitation par les ions argentiques des Br-Cl-I- CN- et SCN-

1-a Meacutethode de dosage des thiocyanates

Lion SCN- AgSCN [Fe(SCN)n](n-3)- fortement coloreacute en rouge et notamment [Fe(SCN)4]- Il y a donc compeacutetition entre les ions argentiques et ferriques vis-agrave-vis du thiocyanate

- Lrsquoabsence presque totale des indicateurs nous impose de proceacuteder agrave des meacutethodes en retour

Ksp [Ag+][SCN-] = Ks = 10-12 dougrave [SCN-] = [Ag+]

Lorsque le point deacutequivalence est atteint [SCN-] = radic Ks

[SCN-]1 lt [SCN-]2

Donc en preacutesence dun meacutelange des deux cations et dun deacutefaut dion thiocyanate cest le thiocyanate dargent qui preacutecipite avant que ne se forme le complexe coloreacute

Indicateurs On utilise lalun de fer ammoniacal ou sulfate de fer et dammonium

1-b Meacutethode de Charpentier Volhard

- Cette meacutethode par retour est neacutecessaire en raison de labsence dindicateur en milieu acide pour les halogeacutenures Elle seffectue donc en deux temps

- Preacutecipitation du deacuteriveacute argentique insoluble par un excegraves de solution de nitrate drsquoargent titreacutee

- Dosage de lexcegraves de Ag+ par une solution titreacutee de SCN- en preacutesence dalun de fer ammoniacal et en milieu nitrique

Ag+ + X- AgX

+ Ag+ AgSCN

Fe+3 + 4SCN [Fe(SCN)4]-

NB ce dosage se deacuteroule en milieu acide nitrique 1N

c-agrave-d

- Si KspAgSCN gt KspAgX il nya pas de risque derreur cest le cas des iodures et des bromures

- Si KspAgSCN lt KspAgX il y a risque de deacuteplacement de lhalogeacutenure preacutecipiteacute par les SCN- en excegraves qui entraicircne une erreur par deacutefaut Cest le cas des chlorures puisque le Ksp du thiocyanate est 100 fois plus faible que celui du Cl-

- Pour eacuteviter cette erreur il est tregraves souhaitable deacuteliminer le chlorure dargent par filtration

- Remarque il faut tenir compte eacutegalement de la diffeacuterence de solubiliteacute entre lhalogeacutenure dargent et le thiocyanate dargent

2 Argentomeacutetrie en milieu sensiblement neutre

a Meacutethode de Mohr

-Elle consiste agrave ajouter agrave la solution dhalogeacutenure agrave doser le AgNO3 -Le dosage est termineacute lorsque laddition dune goutte de solution argentique nentraicircne

aucune preacutecipitation -Cette meacutethode mise au point par Gay-Lussac est longue et peu preacutecise

-Afin de deacuteterminer facilement le PE Mohr avait proposeacute drsquoajouter comme indicateur = une solution de chromate de potassium

Le principe de la technique

-Cest un dosage volumeacutetrique direct Dans un premier temps les ions chlorures sont meacutelangeacutes agrave des ions Ag+ Il se forme un preacutecipiteacute dAgCl

Ag+ + Cl- AgCl

- Lorsque la totaliteacute des ions chlorures a preacutecipiteacute les ions Ag+ sont disponibles pour reacuteagir avec lindicateur utiliseacute Leacutequivalence est donc mise en eacutevidence par lapparition dune couleur rouge-orange

2Ag+ + CrO42 - Ag2CrO4

Concentration en Indicateur [Ag+] = radic KspAgCl asymp 10-5 Donc la concentration en chromate doit ecirctre [CrO4

2-] times [10-5]2 asymp 10-12 soit [CrO42-] asymp 10-2 M

En reacutealiteacute cette concentration 001 M est beaucoup trop grande pour permettre lobservation convenable du virage La concentration optimale est 0003 M

choix du pH est important En effet 1048707 agrave pH lt 6 le chromate dargent sel dacide faible se dissout 1048707 dautre part agrave pH gt 105 loxyde dargent AgO brun se forme preacutefeacuterentiellement en raison de sa plus grande insolubiliteacute

Utilisations et limites La meacutethode de Mohr permet le dosage des Cl- et Br-

1048707 Les iodures ne sont pas dosables dune faccedilon preacutecise rarr caractegravere adsorbant de liodure dargent et de sa coloration jaune

1048707 Les cyanures dont les solutions ont un pH tregraves eacuteleveacute ne sont pas - non plus- justiciables par cette meacutethode

c Meacutethode de Fajans

- Ladsorption dans ce cas est non seulement utile mais neacutecessaire - Tous les halogeacutenures dargent ont un certain pouvoir adsorbant qui augmente du Cl- au Br- et agrave I-

Ladsorption consiste agrave la fixation dions par le preacutecipiteacute dhalogeacutenure dargent

- Lors du dosage dun halogeacutenure par le nitrate dargent avant le point deacutequivalence les grains de preacutecipiteacute baignent dans une solution contenant un excegraves dions halogeacutenure

- Ces charges repoussent les autres anions et nattirent que tregraves peu les cations dont les halogeacutenures sont solubles (H+ Na+ K+ etchellip)

- Ce sont donc ces ions qui sadsorbent preacutefeacuterentiellement sur le preacutecipiteacute qui de ce fait prend une charge neacutegative

Degraves que le point deacutequivalence est deacutepasseacute le preacutecipiteacute est au contraire ce sont alors les ions Ag+ qui sadsorbent et le preacutecipiteacute chargeacute attire dautres anions

cest le cas des anions coloreacutes de la fluoresceacuteine Ou de ses deacuteriveacutes bromeacute (eacuteosine) ou chloreacute (dichlorofluoresceacuteine)

Apregraves le point deacutequivalence lanion coloreacute (jaune) est attireacute par le preacutecipiteacute qui est alors chargeacute positivement par ladsorption dions argentiques

Coloration rose saumon par adsorption de la fluoresceacuteine sur le chlorure dargent

Ex titrage de NaCl par AgNO3

- le preacutecipiteacute de AgCl adsorbe des ions Cl- qui attirent des ions Na+

Au PE et au-delagrave le preacutecipiteacute de AgCl adsorbe des ions Ag+ qui attirent des ionsNO3-

Il apparaicirct une coloration rose saumon sur le preacutecipiteacute

F- Courbes de titrage

Drsquoabord on explique comment calculer les courbes de titrage dans le cas ougrave des anions reacuteagissent avec lion argent pour former un preacutecipiteacute de solubiliteacute limiteacutee

Les courbes de titrage sont geacuteneacuteralement preacutesenteacutees sous la forme de graphiques ougrave lon porte le pAg en fonction du volume de nitrate dargent

A Les courbes de titrage lorsquun seul anion est agrave doser

- Les courbes de titrage pour un seul anion se calculent dune maniegravere tout agrave fait analogue agrave celle de titrage des acides forts et des bases fortes

- log Ksp = - log ([Ag+] [Cl-]) = - log [Ag+] - log [Cl-] pKsp = pAg + pCl Comparons cette expression avec celle-ci pKe = pH + pOH Il existe ainsi une analogie entre les deux expressions

- La seule diffeacuterence reacuteside en ce que le produit de solubiliteacute du preacutecipiteacute remplace le produit ionique de leau

Figure 1 Effet de la concentration du reacuteactif titrant sur les courbes de titrage A 50 ml de NaCl 005 M par AgNO3 01 M B 50 ml de NaCl 0005 M par AgNO3 001

Figure 2 Effet de Ksp sur les courbes de titrage 50 ml dune solution 005 M dun anion ont eacuteteacute titreacutes par AgNO3 01 M

B Les courbes de titrage lorsquil y a meacutelange danions

Figure 3 Courbes de titrage de 50 ml dune solution 008 M en Cl- et 005 M en I- (ou en Br-)

Cours solubiliteacute 2egraveme eacutenneacutee 2015

A- Consideacuterations geacuteneacuterales

A-1-Deacutefinition de la solubiliteacute

La solubiliteacute laquo S raquo est deacutefinie comme eacutetant

quantiteacute maximale de corps que lrsquoon peut dissoudre

dans un volume deacutetermineacute du solvant liquide

Lorsque cette quantiteacute normale est

atteinte la solution est satureacutee et lorsque

cette quantiteacute est deacutepasseacutee on dit qursquoil y a

preacutecipitation du soluteacute

Introduction

Sels peu soluble Equilibres en solution heacuteteacuterogegravene

apolaire

peu solubles

(MX M+ + X-)

Drsquoougrave

[MX] MX M+ + X-

Solide

dissous

Solide

solution

satureacutee

MnXm nMm+ + mXn-

|Mm+|n |Xn-|m

|MnXm|

solution = S

(solubiliteacute)

Ksp = |Mm+| |Xn-|

solide

AgCl KSP = [Ag+][Cl-] 1810-10 977

AgBr KSP = [Ag+][Br-] 510-13 143

AgI KSP = [Ag+][I-] 4510-17 1634

Ag2CrO4 KSP = [Ag+]2[CrO4-2] 1310-12 1188

AgOH KSP = [Ag+][OH-] 210-8 739

Mg(OH)2 KSP = [Mg+2][OH-]2 510-12 113

BaSO4 KSP = [Ba+2][SO4-2] 1110-10 995

Pb3(PO4)2 KSP = [Pb+2]3[PO4-3]2 7910-43 421

MmXn mMn+ + nXm-

S mS nS

| Mn+| = mS

|Xm-| = nS

Ksp = |Aq+|p |Bp-|q

de la solution = S

ApBq pAq+ + qBp-

|Aq+| = pS |Bp-| = qS

Ksp = |pS|p |qS|q

= Sp+q ppqq

Sp+q = Ksp ppqq

p+q Ksp

Exemple 12

solubiliteacute

avec MnXm raquo

AgCl Ag+ + Cl- 2

Ksp = 10-10

|Ba2+| |SO42-| = Ksp |Ba2+| = |SO4

2-| = Ksp = 105-

|Ba2+| = 1010- 10 2-

|Ba2+| = 108-

Complexe anionique

qui est soluble

redissolution

peu soluble

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

apolaire

peu solubles

(MX M+ + X-)

Drsquoougrave

[MX] MX M+ + X-

Solide

dissous

Solide

solution

satureacutee

MnXm nMm+ + mXn-

|Mm+|n |Xn-|m

|MnXm|

solution = S

(solubiliteacute)

Ksp = |Mm+| |Xn-|

solide

AgCl KSP = [Ag+][Cl-] 1810-10 977

AgBr KSP = [Ag+][Br-] 510-13 143

AgI KSP = [Ag+][I-] 4510-17 1634

Ag2CrO4 KSP = [Ag+]2[CrO4-2] 1310-12 1188

AgOH KSP = [Ag+][OH-] 210-8 739

Mg(OH)2 KSP = [Mg+2][OH-]2 510-12 113

BaSO4 KSP = [Ba+2][SO4-2] 1110-10 995

Pb3(PO4)2 KSP = [Pb+2]3[PO4-3]2 7910-43 421

MmXn mMn+ + nXm-

S mS nS

| Mn+| = mS

|Xm-| = nS

Ksp = |Aq+|p |Bp-|q

de la solution = S

ApBq pAq+ + qBp-

|Aq+| = pS |Bp-| = qS

Ksp = |pS|p |qS|q

= Sp+q ppqq

Sp+q = Ksp ppqq

p+q Ksp

Exemple 12

solubiliteacute

avec MnXm raquo

AgCl Ag+ + Cl- 2

Ksp = 10-10

|Ba2+| |SO42-| = Ksp |Ba2+| = |SO4

2-| = Ksp = 105-

|Ba2+| = 1010- 10 2-

|Ba2+| = 108-

Complexe anionique

qui est soluble

redissolution

peu soluble

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

peu solubles

(MX M+ + X-)

Drsquoougrave

[MX] MX M+ + X-

Solide

dissous

Solide

solution

satureacutee

MnXm nMm+ + mXn-

|Mm+|n |Xn-|m

|MnXm|

solution = S

(solubiliteacute)

Ksp = |Mm+| |Xn-|

solide

AgCl KSP = [Ag+][Cl-] 1810-10 977

AgBr KSP = [Ag+][Br-] 510-13 143

AgI KSP = [Ag+][I-] 4510-17 1634

Ag2CrO4 KSP = [Ag+]2[CrO4-2] 1310-12 1188

AgOH KSP = [Ag+][OH-] 210-8 739

Mg(OH)2 KSP = [Mg+2][OH-]2 510-12 113

BaSO4 KSP = [Ba+2][SO4-2] 1110-10 995

Pb3(PO4)2 KSP = [Pb+2]3[PO4-3]2 7910-43 421

MmXn mMn+ + nXm-

S mS nS

| Mn+| = mS

|Xm-| = nS

Ksp = |Aq+|p |Bp-|q

de la solution = S

ApBq pAq+ + qBp-

|Aq+| = pS |Bp-| = qS

Ksp = |pS|p |qS|q

= Sp+q ppqq

Sp+q = Ksp ppqq

p+q Ksp

Exemple 12

solubiliteacute

avec MnXm raquo

AgCl Ag+ + Cl- 2

Ksp = 10-10

|Ba2+| |SO42-| = Ksp |Ba2+| = |SO4

2-| = Ksp = 105-

|Ba2+| = 1010- 10 2-

|Ba2+| = 108-

Complexe anionique

qui est soluble

redissolution

peu soluble

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

Drsquoougrave

[MX] MX M+ + X-

Solide

dissous

Solide

solution

satureacutee

MnXm nMm+ + mXn-

|Mm+|n |Xn-|m

|MnXm|

solution = S

(solubiliteacute)

Ksp = |Mm+| |Xn-|

solide

AgCl KSP = [Ag+][Cl-] 1810-10 977

AgBr KSP = [Ag+][Br-] 510-13 143

AgI KSP = [Ag+][I-] 4510-17 1634

Ag2CrO4 KSP = [Ag+]2[CrO4-2] 1310-12 1188

AgOH KSP = [Ag+][OH-] 210-8 739

Mg(OH)2 KSP = [Mg+2][OH-]2 510-12 113

BaSO4 KSP = [Ba+2][SO4-2] 1110-10 995

Pb3(PO4)2 KSP = [Pb+2]3[PO4-3]2 7910-43 421

MmXn mMn+ + nXm-

S mS nS

| Mn+| = mS

|Xm-| = nS

Ksp = |Aq+|p |Bp-|q

de la solution = S

ApBq pAq+ + qBp-

|Aq+| = pS |Bp-| = qS

Ksp = |pS|p |qS|q

= Sp+q ppqq

Sp+q = Ksp ppqq

p+q Ksp

Exemple 12

solubiliteacute

avec MnXm raquo

AgCl Ag+ + Cl- 2

Ksp = 10-10

|Ba2+| |SO42-| = Ksp |Ba2+| = |SO4

2-| = Ksp = 105-

|Ba2+| = 1010- 10 2-

|Ba2+| = 108-

Complexe anionique

qui est soluble

redissolution

peu soluble

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

MnXm nMm+ + mXn-

|Mm+|n |Xn-|m

|MnXm|

solution = S

(solubiliteacute)

Ksp = |Mm+| |Xn-|

solide

AgCl KSP = [Ag+][Cl-] 1810-10 977

AgBr KSP = [Ag+][Br-] 510-13 143

AgI KSP = [Ag+][I-] 4510-17 1634

Ag2CrO4 KSP = [Ag+]2[CrO4-2] 1310-12 1188

AgOH KSP = [Ag+][OH-] 210-8 739

Mg(OH)2 KSP = [Mg+2][OH-]2 510-12 113

BaSO4 KSP = [Ba+2][SO4-2] 1110-10 995

Pb3(PO4)2 KSP = [Pb+2]3[PO4-3]2 7910-43 421

MmXn mMn+ + nXm-

S mS nS

| Mn+| = mS

|Xm-| = nS

Ksp = |Aq+|p |Bp-|q

de la solution = S

ApBq pAq+ + qBp-

|Aq+| = pS |Bp-| = qS

Ksp = |pS|p |qS|q

= Sp+q ppqq

Sp+q = Ksp ppqq

p+q Ksp

Exemple 12

solubiliteacute

avec MnXm raquo

AgCl Ag+ + Cl- 2

Ksp = 10-10

|Ba2+| |SO42-| = Ksp |Ba2+| = |SO4

2-| = Ksp = 105-

|Ba2+| = 1010- 10 2-

|Ba2+| = 108-

Complexe anionique

qui est soluble

redissolution

peu soluble

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

(solubiliteacute)

Ksp = |Mm+| |Xn-|

solide

AgCl KSP = [Ag+][Cl-] 1810-10 977

AgBr KSP = [Ag+][Br-] 510-13 143

AgI KSP = [Ag+][I-] 4510-17 1634

Ag2CrO4 KSP = [Ag+]2[CrO4-2] 1310-12 1188

AgOH KSP = [Ag+][OH-] 210-8 739

Mg(OH)2 KSP = [Mg+2][OH-]2 510-12 113

BaSO4 KSP = [Ba+2][SO4-2] 1110-10 995

Pb3(PO4)2 KSP = [Pb+2]3[PO4-3]2 7910-43 421

MmXn mMn+ + nXm-

S mS nS

| Mn+| = mS

|Xm-| = nS

Ksp = |Aq+|p |Bp-|q

de la solution = S

ApBq pAq+ + qBp-

|Aq+| = pS |Bp-| = qS

Ksp = |pS|p |qS|q

= Sp+q ppqq

Sp+q = Ksp ppqq

p+q Ksp

Exemple 12

solubiliteacute

avec MnXm raquo

AgCl Ag+ + Cl- 2

Ksp = 10-10

|Ba2+| |SO42-| = Ksp |Ba2+| = |SO4

2-| = Ksp = 105-

|Ba2+| = 1010- 10 2-

|Ba2+| = 108-

Complexe anionique

qui est soluble

redissolution

peu soluble

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

AgCl KSP = [Ag+][Cl-] 1810-10 977

AgBr KSP = [Ag+][Br-] 510-13 143

AgI KSP = [Ag+][I-] 4510-17 1634

Ag2CrO4 KSP = [Ag+]2[CrO4-2] 1310-12 1188

AgOH KSP = [Ag+][OH-] 210-8 739

Mg(OH)2 KSP = [Mg+2][OH-]2 510-12 113

BaSO4 KSP = [Ba+2][SO4-2] 1110-10 995

Pb3(PO4)2 KSP = [Pb+2]3[PO4-3]2 7910-43 421

MmXn mMn+ + nXm-

S mS nS

| Mn+| = mS

|Xm-| = nS

Ksp = |Aq+|p |Bp-|q

de la solution = S

ApBq pAq+ + qBp-

|Aq+| = pS |Bp-| = qS

Ksp = |pS|p |qS|q

= Sp+q ppqq

Sp+q = Ksp ppqq

p+q Ksp

Exemple 12

solubiliteacute

avec MnXm raquo

AgCl Ag+ + Cl- 2

Ksp = 10-10

|Ba2+| |SO42-| = Ksp |Ba2+| = |SO4

2-| = Ksp = 105-

|Ba2+| = 1010- 10 2-

|Ba2+| = 108-

Complexe anionique

qui est soluble

redissolution

peu soluble

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

MmXn mMn+ + nXm-

S mS nS

| Mn+| = mS

|Xm-| = nS

Ksp = |Aq+|p |Bp-|q

de la solution = S

ApBq pAq+ + qBp-

|Aq+| = pS |Bp-| = qS

Ksp = |pS|p |qS|q

= Sp+q ppqq

Sp+q = Ksp ppqq

p+q Ksp

Exemple 12

solubiliteacute

avec MnXm raquo

AgCl Ag+ + Cl- 2

Ksp = 10-10

|Ba2+| |SO42-| = Ksp |Ba2+| = |SO4

2-| = Ksp = 105-

|Ba2+| = 1010- 10 2-

|Ba2+| = 108-

Complexe anionique

qui est soluble

redissolution

peu soluble

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

MmXn mMn+ + nXm-

S mS nS

| Mn+| = mS

|Xm-| = nS

Ksp = |Aq+|p |Bp-|q

de la solution = S

ApBq pAq+ + qBp-

|Aq+| = pS |Bp-| = qS

Ksp = |pS|p |qS|q

= Sp+q ppqq

Sp+q = Ksp ppqq

p+q Ksp

Exemple 12

solubiliteacute

avec MnXm raquo

AgCl Ag+ + Cl- 2

Ksp = 10-10

|Ba2+| |SO42-| = Ksp |Ba2+| = |SO4

2-| = Ksp = 105-

|Ba2+| = 1010- 10 2-

|Ba2+| = 108-

Complexe anionique

qui est soluble

redissolution

peu soluble

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

Ksp = |Aq+|p |Bp-|q

de la solution = S

ApBq pAq+ + qBp-

|Aq+| = pS |Bp-| = qS

Ksp = |pS|p |qS|q

= Sp+q ppqq

Sp+q = Ksp ppqq

p+q Ksp

Exemple 12

solubiliteacute

avec MnXm raquo

AgCl Ag+ + Cl- 2

Ksp = 10-10

|Ba2+| |SO42-| = Ksp |Ba2+| = |SO4

2-| = Ksp = 105-

|Ba2+| = 1010- 10 2-

|Ba2+| = 108-

Complexe anionique

qui est soluble

redissolution

peu soluble

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

Ksp = |pS|p |qS|q

= Sp+q ppqq

Sp+q = Ksp ppqq

p+q Ksp

Exemple 12

solubiliteacute

avec MnXm raquo

AgCl Ag+ + Cl- 2

Ksp = 10-10

|Ba2+| |SO42-| = Ksp |Ba2+| = |SO4

2-| = Ksp = 105-

|Ba2+| = 1010- 10 2-

|Ba2+| = 108-

Complexe anionique

qui est soluble

redissolution

peu soluble

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

solubiliteacute

avec MnXm raquo

AgCl Ag+ + Cl- 2

Ksp = 10-10

|Ba2+| |SO42-| = Ksp |Ba2+| = |SO4

2-| = Ksp = 105-

|Ba2+| = 1010- 10 2-

|Ba2+| = 108-

Complexe anionique

qui est soluble

redissolution

peu soluble

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

avec MnXm raquo

AgCl Ag+ + Cl- 2

Ksp = 10-10

|Ba2+| |SO42-| = Ksp |Ba2+| = |SO4

2-| = Ksp = 105-

|Ba2+| = 1010- 10 2-

|Ba2+| = 108-

Complexe anionique

qui est soluble

redissolution

peu soluble

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

avec MnXm raquo

AgCl Ag+ + Cl- 2

Ksp = 10-10

|Ba2+| |SO42-| = Ksp |Ba2+| = |SO4

2-| = Ksp = 105-

|Ba2+| = 1010- 10 2-

|Ba2+| = 108-

Complexe anionique

qui est soluble

redissolution

peu soluble

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

Ksp = 10-10

|Ba2+| |SO42-| = Ksp |Ba2+| = |SO4

2-| = Ksp = 105-

|Ba2+| = 1010- 10 2-

|Ba2+| = 108-

Complexe anionique

qui est soluble

redissolution

peu soluble

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

|Ba2+| = 1010- 10 2-

|Ba2+| = 108-

Complexe anionique

qui est soluble

redissolution

peu soluble

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

Complexe anionique

qui est soluble

redissolution

peu soluble

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

peu soluble

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

AgNO2 Ag+ + NO2-

Ksp = [Ag+] [NO2-] = 10- 38

HCl H+ + Cl-

NO2- + H+ HNO2

[NO2-] [H+] [NO2

-] [H+]

Ka = [HNO2] =

[HNO2] Ka

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

[Ag+] = S

S = [NO2-]totale

S = [NO2-] + [HNO2]

S = [NO2-] + [NO2

-] [H+] Ka

S = [NO2-] ( 1 + [H+] Ka)

Drsquoougrave

Ksp = S

1 + [H+] Ka

S2 = Ksp ( 1 + [H+] Ka )

S = Ksp [1 + [H+] Ka ]

S augmente

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

1 0178

2 00576

3 00218

4 00138

5 00127

6 001265

7 00126

8 00126

9 00126

+ le pH

augmente

diminue

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

AgCl Ag+ + Cl-

Ksp = [Ag+] [Cl-] = 178 10-10

Ag+ + 2 NH3 [Ag(NH3)2]+

[Ag(NH3)2]+

Ks = [Ag(NH3)2]+ = Ks [Ag+] [NH3]

[Ag+] [NH3]2 25

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

S = [Cl-]

S = [Ag+]T

S = [Ag+] + [Ag(NH3)2]

S = [Ag+] + Ks [Ag+] [NH3]2

S = [Ag+] ( 1 + Ks [NH3]2 )

[Ag+] = S (1 + Ks [NH3]2)

Ksp = S S (1 + Ks[NH3]2)

S2 = KSp (1 + Ks [NH3]2)

S = KSp (1 + Ks [NH3]2)

augmente

effectivement la

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

peu soluble

Ksp1 = [Ag+] [Cl-] = 178 10-10

S = Ksp1 = 133 10-5

SCN- + Ag+ AgSCN

Ksp2 = [Ag+] [SCN-] = 10-12 27

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

C + C2 + 4 KSp1(1 + Ksp2 Ksp1)

2 ( 1 + Ksp2 Ksp1)

Or Ksp2Ksp1 = 10-12178 10-10 = 06 10-2 ltlt 1

S = frac12 ( C + C2 + 4 KSp1) 28

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

concentrations

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

AB A- + B+

Ksp = a (A-) a(B+) [A-]A [B+]B = Ksp

[A-][B+] = KSp A B

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

AgI le KSp = 45 10-17

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

[Ag+][I-] = 47 10-17

KsAgI 47 10-17

[Ag+] = = [I-] [I-]

[Ag+][Br-] = 5 10-13

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

On obtient 45 10-17

[Br-] = 5 10-13 [I-]

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

KsAgBr 5 10-13

[Ag+] = = [Br-] [Br-]

[Cl-] 18 10-10

= = 36 102 [Br-] 5 10-13

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

Ksp Ag2CrO4 = 13 10-12

[Ag+]2 times [CrO42-] = 13 10-12

13 10-12

[Ag+] = radic

[ CrO42-]

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

[SCN-]1 lt [SCN-]2

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

Ag+ + X- AgX

+ Ag+ AgSCN

c-agrave-d

Ag+ + Cl- AgCl

c-agrave-d

Ag+ + Cl- AgCl

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SOLUBILITE / PRECIPITATION - univ.ency …univ.ency-education.com/.../1/0/13102001/pharm2an16_ch_anal-solubil… · Introduction Sels peu soluble ... B- Influence de l’environnement