Chemistry 12 Name: Solubility Equilibrium III Date: Block
5
Chemistry 12 Solubility Equilibrium III Name: Date: Block: 1. One Source vs. Two Source Solubility Problems 2. Challenging Solubility Problems 3. Prediction of Forming a Precipitate One Source vs. Two Source Solubility Problems One Source Two Source • Both ions come from the same salt (source) PbI2(s) ⇋ Pb 2+ (aq) +2I - (aq) • Both ions come from a different salt (source) Pb(NO3)2(s) ⇋ Pb 2+ (aq) + 2 NO3 - (aq) KI(s) ⇋K + (aq) + I - (aq) PbI2(s) ⇋ Pb 2+ (aq) +2I - (aq) • Ion concentrations are related through mole ratio v 1:1 ratio = v 1:2 ratio = v 1:3 ratio = v 2:3 ratio = • Related through Ksp • Ex: Find the [I - ] if [Pb 2+ ] = 4.5 x 10 -3 M.
Transcript of Chemistry 12 Name: Solubility Equilibrium III Date: Block
Chemistry12SolubilityEquilibriumIII
Name:Date:Block:
1. OneSourcevs.TwoSourceSolubility
Problems2. ChallengingSolubilityProblems3. PredictionofFormingaPrecipitate
OneSourcevs.TwoSourceSolubilityProblems
OneSource TwoSource• Bothionscomefromthesamesalt
(source)
PbI2(s)⇋Pb2+(aq)+2I-(aq)
• Bothionscomefromadifferentsalt(source)
Pb(NO3)2(s)⇋Pb2+(aq)+2NO3-(aq) KI(s)⇋K+(aq)+I-(aq)
PbI2(s)⇋Pb2+(aq)+2I-(aq)
• Ionconcentrationsarerelatedthroughmoleratiov 1:1ratio=
v 1:2ratio=
v 1:3ratio=
v 2:3ratio=
• RelatedthroughKsp• Ex:Findthe[I-]if[Pb2+]=4.5x10-3M.
ChallengingSolubilityProblems1.Asolutionhasaconcentrationofcalciumionsequalto2.5x10-2M.Whatisthemaximumconcentrationofsulphateionsallowedtobeaddedwithoutcausingprecipitation?2.Determinethemaximum[Na2CO3]thatcanexistin1.0Lof0.0010MBa(NO3)2withoutformingaprecipitate.
A.2.6x10-12M B.2.6x10-9MC.2.6x10-6M D.5.1x10-5M
3.Whatisthemaximum[Sr2+]thatcanexistinasolutionof0.10MNa2SO4?
A.3.4x10-7M B.3.4x10-6M C.1.7x10-6MD.5.8x10-4M
4.When100.0mLof4.0x10-2MCaCl2isaddedto150.0mLof2.9x10-2MNaOH,aprecipitatejuststartstoform.WhatistheKspofthisprecipitate?
• Writea(balanced)doublereplacementreaction.
• Whatisthepossibleprecipitate?WritetheKspexpression.
• Calculatethedilutedconcentrationsofeachion.
• CalculatetheKspvalue.5.Upto15.0gofBaCl2canbedissolvedin2.5LofAl2(SO4)3withoutaprecipitatebeingformed.Find[Al2(SO4)3].
• Writethedoublereplacementreaction.(Whatisthesolute?Whatisthesolvent?)
• Whatisthepossibleprecipitatethatcouldbeformed?WritetheKspexpressionanddetermineitsvaluefromthedatabooklet.
• LookingattheKspexpression,isthereanionconcentrationvaluethatcouldbedetermined?
Worksheet3.3
PredictionofFormingaPrecipitateWhentwodifferentsolutionsaremixed,wecanpredictwhetheraprecipitatewillform.TheKspvaluerepresentsthemaximumproductoftheionconcentrationsinasaturatedsolution.Ifanequilibriumisnotpresentinsolution,thenwecalculateatrialionproduct(TIP)–(alsocalledatrialKspvalueorreactionquotient,Q)
IfTrialKsp>ActualKsp–aprecipitateforms.
IfTrialKsp<ActualKsp–noprecipitateforms.
IfTrialKsp=ActualKsp–thesolutionissaturated.
X2Y(s)⇋2X++Y2-
Ksp=Example.(1)Willaprecipitateformwhen23mLof0.020MNa2CO3isaddedto12mLof0.010MMgCl2?
• Writeabalancedequation.Whatistheprecipitatethatwillpotentiallyform?(Usethesolubilitytable)
• Whataretheconcentrationsofeachoftheseions?
• CalculatethevalueofTIP(TrialKsp)
• ComparetheTIP(TrialKsp)withtherealKsp.Willaprecipitateform?
(2)Willaprecipitateformwhen8.5mLof6.3x10-2Mlead(II)nitrateisaddedto1.0Lof1.2x10-3Msodiumiodate?(3)Willaprecipitateformwhen1.5mLof4.5x10-3Mammoniumbromateisaddedto120.5mLof2.5x10-3Msilvernitrate?HebdenWorkbookPg.98#56-69
