Chemistry12SolubilityEquilibriumII

Name:Date:Block:

1. FormingaPrecipitate2. SolubilityProductConstant(OneSource

ofIons)FormingaPrecipitateExample:AsolutionmaycontaintheionsCa2+,Sr2+andZn2+.Howwouldyouprecipitatetheionsoutofsolutionindividually?Describeyouranswerusingaflowchart.

• Allarecations-thereforeanadditionofan_______________willprecipitateoutthesecations.

• Therearealso_______________________inthesolutiontohelpbalanceoutthecharge.

• WhatcanprecipitateoutCa2+?

• WhatcanprecipitateoutSr2+?

• WhatcanprecipitateoutZn2+?

• Whatneedstobeaddedfirst?

Asaflowchart:

Ca2+,Sr2+,Zn2+

Practice:1. Foreachofthefollowingsolutions,describeaprocesstoindividuallyremoveeachion.Besuretolist

thecompoundsthatyouaddinorder,andthemethodofremovingtheprecipitate.

a. Ag+Ba2+andBe2+

b. Br-,SO42-andS2-

c. OH-,PO43-andS2-

d. Cr3+,Ca2+andMg2+

HebdenWorkbookPg.90#26–36

SolubilityProductConstantKsp(OneSourceofIons)Inasaturatedsolution,equilibriumisestablishedbetweenthedissolvingandrecrystallizationofasalt.

AB(s)⇋A+(aq)+B-(aq) Keq=Ksp=Thesolubilityproductconstant,_________,isthe_______________ofthe_________________________________________ina________________________solutionraisedtothepowerofthecoefficientsintheequilibrium.

LabSimulation:Salts&SolubilitySolubilityCurves

Considerthegraphbelow:

a) Ifyouput40gofNH4Clin100mLofwaterat90oC,willyoubeabletoformasaturatedsolution?

b) ApproximatelyhowmanymoregramsofNH4Clcouldyouadduntilitis

saturated?

c) Ifyouput60gofKNO3into100mLofwaterat20oCandgraduallyheatthesolution,whatwillyouobserve?

d) Ifyoudissolve100gofbothNaNO3andKNO3in100mLofwaterat90oCandthencoolthemixtureto10oC,whichsaltwillformcrystalsfirst?

e) Ce2(SO4)3isanunusualsubstanceasitdoesnotfollowtheusualtrend.WhatisunusualaboutCe2(SO4)3?

Themolarsolubilityofasubstanceisthemolarconcentrationofasoluteinasaturatedsolution.

MOLERATIOWILLBEVERYIMPORTANTINTHISUNIT!!

WeneedtowriteouttheIONIZATION/DISSOCIATIONequationtofigureouttheratio.

Solubility=“s”

BaCO3(s)⇋____Ba2+(aq)+____CO32-(aq)Ratioofions:Ksp=Solubility=

Fe(OH)2(s)⇋____Fe2+(aq)+____OH-(aq)

Ratioofions:Ksp=Solubility=

Fe(OH)3(s)⇋____Fe3+(aq)+____OH-(aq)

Ratioofions:Ksp=Solubility=

Sr3(PO4)2(s)⇋____Sr2+(aq)+____PO43-(aq)

Ratioofions:Ksp=1.0x10-31Solubility=

Solubility(M)àKsp(1)ThemolarsolubilityofCaSO4is8.4x10-3Mataparticulartemperature.CalculateitsKsp.

• Whatistheequationrepresentingtheequilibrium?

• WritetheKspexpressionandsubstitutetheconcentrationofionsintotheKspexpression:(2)Thesolubilityoflead(II)chlorideis4.4g/L.CalculateitsKsp.(3)Astudentpreparesasaturatedsolutionbydissolving5.5x10-5molofAl(OH)3in500.mLofsolution.CalculatetheKspofAl(OH)3.(4)Astudentevaporated150.mLofasaturatedsolutionofmagnesiumphosphate.If0.16gofsoluteremains,calculatetheKsp.(5)CalculatetheKspofsilveroxalateifthesolubilityis0.033g/L.(6)Acompoundhasasolubilityof7.1x10-5Mat250C.AccordingtoitsKsp,thecompoundis:

A.CuS B.AgBr C.CaCO3 D.CaSO4

KspàSolubility(M)(1)Calculatethemolarsolubilityofiron(II)hydroxidefromitsKsp.(2)Calculatethemolarsolubilityofiron(III)hydroxidefromitsKsp.(3)Whichofthefollowingsubstanceshasthelowestsolubility? A.BaS B.CuS C.FeS D.ZnS(4)Howmanymolesofdissolvedsolutearepresentin100.0mLofasaturatedSrCO3solution? A.5.6x10-11mol B.2.4x10-6mol C.2.4x10-5mol D.2.4x10-4molWorksheet3.2HebdenWorkbookPg.95#42–55

IonizationEquationExtraPractice:- Representsthesaltbreakingapartintoions

o NaClà____Na++____Cl-- IfthesaltwereCaCl2

o CaCl2à____Ca2++____Cl-- Moleratiosrepresenttherelativeamountsofionsinsolution

NaCl(aq) à Na+(aq) + Cl-(aq)

1.0M

CaCl2(aq) à Ca2+(aq) + 2Cl-(aq)

1.0M Practice:

1. 0.25MKOH

2. 0.75MSrCl2

3. 0.20MNH4NO3

4. 0.45MAg2CrO4

5. 0.60MPb(IO3)2

6. 0.011MMg(OH)2

7. 0.45MBaCO3

8. 0.50M(NH4)2SO3