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8/12/2019 Chap 17 No Titrate Calc No Clicker(2)
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Chapter 17:
Additional AqueousEquilibria
Chemistry the Central Science,12thed
Dr. Stacey Gulde
1
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Common-Ion Effect Common ion effectshiftin equilibrium caused
by adding anion involvedin the equilibrium
AKA Le ChteliersPrinciple
If add NaC2H3O2, what happens?
C2H3O2-causes equilibriumto shift Thus, [H+]decrease& pH becomes morebasic
Dissociationof a weakelectrolyte (ie. HC2H3O2) decreaseswhen a strongelectrolyte (ie. NaC
2
H3
O2
) containing acommon ion (ie. C2H3O2
-) is added2
)()((aq) 232232 aqOHCaqHOHHC
C2H3O2-Na+
breaks up into ions
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Sample Problems1. Calculate the pH of a 0.50M HF solution.
3
)(aqHFI
C
E
0.50M 0 0
xx-x
0.50x xx
4108.6 x]50.0[
]][[
x
xxKa
]50.0[
][
108.6
24 x
x
Mx 018.0 ][
H
100]50.0[
]018.0[% xI %6.3% I
(Assumption OK)
]018.0log[pH
74.1pH
Check 5% Rule:
Appendix D
Ignore x
(W. Acid)
)()( aqFaqH
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Sample Problems2. Calculate the pH of a 0.50M HF solution when 0.10M
NaF is added.
4
4108.6 x]50.0[]10.0][[
xxxKa
]50.0[
]10.0][[108.6 4
xx
Mx 0034.0 ][
H
100]50.0[
]0034.0[% xI
%68.0% I
]0034.0log[pH
47.2pH
More basic
)()()( aqFaqHaqHF
I
C
E
0.50M 0 0.10M
xx-x
0.50x 0.10+xx
Ignore x
(W. Acid)
(Common
Ion)
[HF] only:pH=1.74
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Buffer
Solutions Buffersweakacid/base & conjugateacid/base (salt)
Should have similarconcentrations
Sample Prob. #2: 0.50M HF with 0.10M NaF
Naturalbuffers:
Human blood maintains pH of 7.4
Seawatermaintains pH of 8.1-8.3
CalculatingpH of a buffer:
Previous sample problem #2 (pH=2.47)
OR use Henderson-Hasselbalch eq. (H-H eq)
5
)()()( aqFaqHaqHF (W. Acid) (CB)
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Henderson-Hasselbalch Eq
Sample Problem #2 Revisited: Calculate pH of a0.50M HF solution when 0.10M NaF is added.
6
acidbase
pKpH a log
)()()( aqFaqHaqHF Ka= 6.8x10-4
4108.6log xpH
47.2
pH
50.0
10.0log
70.017.3
0.50M 0.10M
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Adding Strong Acids/Bases
to a Buffer Solutions Buffer Purpose: resistpHchange when limited
amountsof strongacid or base is added
Lab Exp. 18
How happen:
Addedacid or base reactsw/something in the buffer
Addedacid or base is limiting
Ex. Buffer:
7
Buffer Demo
HA A-
Buffered soln
)()()( aqAaqHaqHA (W. Acid) (CB)
http://www.youtube.com/watch?v=g_ZK2ABUjvAhttp://www.youtube.com/watch?v=g_ZK2ABUjvA8/12/2019 Chap 17 No Titrate Calc No Clicker(2)
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Adding a substance:
1. H+added: REACTS w/ ____ in buffer
Producing more ____
2. OH-added: REACTS w/ ____ in buffer
Producing more ____
8
HA A-
Buffered soln
)()()( aqAaqHaqHA (W. Acid) (CB)
H+(aq) +A-(aq) HA(aq)
HA A-
Buffered soln
OH-(aq) + HA(aq) A-(aq)
HA A-
HA A-
A-
HA
HA
A-
+H2O(l)
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Adding Strong Acid/Base
to a Buffer Solution If the addedacid/base is strong, it isALL used up
To calculate pH you use:a) ICE (must use MOLES!)
b) H-Heq.(must use M)
9
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Sample Problems1. Calculate the pH of a 1.0L solution containing 0.10M NaF &
0.50M HF, when 9.5mL of 2.1M HCl is added.(assume minimal/no volume change)
HF(0.50M)
NaF(0.10M)
&
1.0L Solnalready made
BUFFER!
Buffer:
0.50M 0.10MH+(aq) + F-(aq)HF(aq)ADD HCl
H+(aq)
RXN:
+ F-(aq)HF
(aq)
Added: H+(aq) reacts w/
W. Acid!
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Sample Problems1. Calculate the pH of a 1.0L solution containing 0.10M NaF &
0.50M HF, when 9.5mL of 2.1M HCl is added.(assume minimal/no volume change)
+0.020-0.020
0.08mol 0.52mol
-0.020
0
I
C
E
a) ICE Stoichiometry: (MOLES)Change by lower reactant value
(0.10M)(1.0L)(2.1M)(0.0095L)
0.10mol0.020 mol
(0.50M)(1.0L)
0.50mol
1.0L 1.0L
b) H-H: (M)
AcidBase
pKpH a log
4108.6log xpH
81.017.3 pH
36.2pH
52.008.0log
H+(aq) + F-(aq) HF(aq)
RXN:
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Sample Problems2. Calculate the pH of a 1.0L solution containing 0.10M NaF &
0.50M HF, when 9.5mL of 2.1M NaOH is added.(assume minimal/no volume change)
12
Buffer=
a) ICE Stoich.: (MOLES) b) H-H eq (M)
0
+0.0200-0.020
0.48mol 0.12mol0
-0.020
0
I
C
E
(0.50M)(1.0L)(2.1M)(0.0095L)
0.50mol0.020 mol
(0.10M)(1.0L)
0.10mol
1.0L 1.0L
0.50M 0.10M
AcidBase
pKpH a log
4108.6log xpH48.012.0log
60.017.3 pH
57.2pH
OH-(aq)+ HF(aq) +F-(aq)H2O()
H+(aq) + F-(aq)HF(aq)
Added: OH-(aq) reacts w/
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pH Comparison 0.50M HF: pH = 1.74
Buffer0.50M HF & 0.10M NaF: pH = 2.47 pH inc. (more basic) due presence of a common ion
Buffer0.50M HF & 0.10M NaF w/added9.5mL of
2.1M HCl: pH = 2.35 pH dec. (more acidic) due additionof acid
Buffer0.50M HF & 0.10M NaF w/added9.5mL of2.1M NaOH: pH = 2.59
pH inc. (more basic) due additionof base 13
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Sample Problem(What ifVolume changes?)
1. Calculate the pH of a solution formed by mixing 65mL of0.20M NH4Cl with 75mL of 0.15M NH3. W. Base!
NH3
NH4Cl
NH3
NH4Cland
75mL0.15M65mL
0.20M
65mL+75mL
??M
Buffer:
To Find Initial:Convert original M to moles,
then back toMusing Total Vol
=140.mL
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Sample Problem(What ifVolume changes?)
1. Calculate the pH of a solution formed by mixing 65mL of0.20M NH4Cl with 75mL of 0.15M NH3.
BUFFER, MUSTuse ICE table!!
15
)(NH4 aq
0-x
0.093+x0
+x
0.080-x
I
C
E
(0.20M)(065L)(0.15M)(0.075L)
0.013mol0.01125 mol0.140L
)(NH3 aq O(l)H2
0 0
0.140L
0.080M 0.093M
+x
x
5
108.1
x]080.0[
]][093.0[
x
xx
Kb
]080.0[
]][093.0[108.1
5 xx
Mxx5
105.1
][
OH
W. Base!
)(OH aq
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Sample Problem(What ifVolume changes?)
1. Calculate the pH of a solution formed by mixing 65mL of0.20M NH4Cl with 75mL of 0.15M NH3.
BUFFER, MUSTuse ICE table!!
16
)(NH4 aq
0-x
0.093+x0
+x
0.080-x
I
C
E
(0.20M)(065L)(0.15M)(0.075L)
0.013mol0.01125 mol0.140L
)(NH3 aq O(l)H2
0 0
0.140L
0.080M 0.093M
+x
x
W. Base!
)(OH aq 100080.0
105.1%
5
xx
I
%019.0% I
]105.1log[5
xpOH
82.4pOH
82.400.14 pH
18.9pH
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Sample Problem (Volume changes?)2. Calculate the pH of a solution formed by mixing 65mL of
0.20M NH4Cl with 75mL of 0.15M NH3& adding 15.3mL
of 0.17M NaOH.
17
O(l)H)(NH 23 aq
-0.0026-0.0026
0.01385mol0mol
+0.0026
0.0104mol
I
C
E
(0.15M)(075L)(0.20M)(0.065L)
0.01125mol0.013 mol
0.155L
)(NH4 aq )(OH- aq
0
VT=65mL+75mL+15.3mL=155.mL
0.155L
0
0
a) ICE Stoich: (MOLES)
(0.17M)(0.0153L)
0.0026 mol
0.00671M 0.0894M
b) H-H: (M)
AcidBase
pKpH a log
14
101
xKK ba
145
101108.1
xxKa
10106.5 xKa
Try on ownBuffer=
Added: OH-(aq) reacts w/
0.15M 0.20MNH4
+(aq) + OH-(aq)NH3(aq)+ H2O(aq)
(NH3is a base, K
b= 1.8x10-5)
Must solve for Ka
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Sample Problem (Volume changes?)2. Calculate the pH of a solution formed by mixing 65mL of
0.20M NH4Cl with 75mL of 0.15M NH3& adding 15.3mL
of 0.17M NaOH.
18
O(l)H)(NH 23 aq
-0.0026-0.0026
0.01385mol0mol
+0.0026
0.0104mol
I
C
E
(0.15M)(075L)(0.20M)(0.065L)
0.01125mol0.013 mol
0.155L
)(NH4 aq )(OH- aq
0
VT=65mL+75mL+15.3mL=155.mL
0.155L
0
0
a) ICE Stoich: (MOLES)
(0.17M)(0.0153L)
0.0026 mol
0.00671M 0.0894M
b) H-H: (M)
AcidBase
pKpH a log
Try on ownBuffer=
Added: OH-(aq) reacts w/
0.15M 0.20MNH4
+(aq) + OH-(aq)NH3(aq)+ H2O(aq)
125.025.9 pH
0671.00894.0
log
38.9pH
10
106.5log
xpH
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Buffer Capacity Buffer Capacityamount of acid/baseadded
before a significantpH change occurs
In demo video: needed to count drops of NaOHadded Took ~30 drops to turn green
Took ~35 drops to turn blue/violet
Depends on conc.of acid/base used to prepare buffer Which has a greater buffering capacity?
19
1 MHF & 1 M NaF0.1M HF & 0.1 M NaF
More initialacid/baseto react with
addedacid/base
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Buffer Range Buffer range - pHrange where buffer is effective
Want conc.of acid/base & conjugate to be similar
Ex: 0.50M HF & 0.10M NaF
If conc of 1 component in buffer is > 10x the conc of theother, buffering action is poor
Choose an acidwhose pKais close to the desired pH
20
pKaofunitpH1Range
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Questions:1. Which of the following will have the worstbuffering
range?
A. 0.1M HA and 0.1M A-
B. 0.2M HA and 0.1M A-
C. 0.1M HA and 1.5M A-
D. 1.0M HA and 1.0M A-
21
Difference ismore than 10x
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Questions:2. You wish to make a buffered solution with a pH=7.0,
which acid will be the best to use?
A. HNO2: Ka = 4.5x10-4 pKa= 3.35
B. HClO: Ka= 3.0x10-8 pKa= 7.52
C. H3PO4: Ka= 7.5x10-3 pKa= 2.12
D. H2CO3: Ka= 4.3x10-7 pKa= 6.37
E. HBrO: Ka= 2.5x10-9 pKa= 8.60
22
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Acid/Base Titration Introduced in Chapter 4
Indicatorschemicals that changecolorwhen a solution turns fromacidic to basic
Phenolphthalein
Acid = Clear
Base = Pink
23
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Acid/Base Titration Titration CurvepHvs. volumeof titrantadded
Titrant- liquid in buret
Equivalence Pointstoichiometric# of moles of acid =
# mols base reacted
Endpointwhere indicator changescolor permanently
Just past the equivalence point
24
TitrationCurve
Equiv. pt
Endpt
http://www.youtube.com/watch?v=yirkozUyG74http://www.youtube.com/watch?v=yirkozUyG74http://www.youtube.com/watch?v=yirkozUyG74http://www.youtube.com/watch?v=yirkozUyG74http://www.youtube.com/watch?v=yirkozUyG748/12/2019 Chap 17 No Titrate Calc No Clicker(2)
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pH at Various
Titration Points 2 types of titrations
1. Strong/Strong
2. Weak/Strong
What is happening to pH @ 4 different points
A. InitialpH
B. Beforeequivalence pt
C. @equivalence pt
D. Afterequivalence pt
25
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pH at VariousTitration Points
1. Strong Acid
&Strong Base
26
1 Strong Ac Strong Base:
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1. StrongAc - StrongBase:(NaOH added to HCl)
A. Initial pH:beforeadding base
NoNaOH added, onlyHCl present
pH =Very acidicB. Beforeequivalencept:
HCl & NaOH react
Baselimiting
Acidexcess
pH=slowlymore basic,b/c less acid in excess
Raises rapidlynear
equivalence pt.27
)(l(aq)a)(a)( 2 lOHCNaqOHNaqHCl
A
100mL0.50M
?mL0.10M
pH=0.30
BpH=0.44
pH=2.17
1 Strong Acid Strong Base:
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C. At equivalencept: HCl & NaOH react
Moles acid=Moles of base
CompletelyNeutralized pH = 7.00
How get pH when only
NaCl & H2O present?- Waterdissociates
28
C
H2O (l) H+(aq) + OH-(aq) 14101 xKw
M101]OH[]H[ 7 x
1. Strong Acid-Strong Base:(NaOH added to HCl)
pH=7.00
)(l(aq)a)(a)( 2 lOHCNaqOHNaqHCl 100mL0.50M
?mL0.10M
1 Strong Acid Strong Base:
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D. After equivalencept: HCl & NaOH react
Acid limiting
Completely consumed
Base excess
pH = slowly more basic
29
D
1. Strong Acid-Strong Base:(NaOH added to HCl)
)(l(aq)a)(a)( 2 lOHCNaqOHNaqHCl 100mL0.50M
?mL0.10M
pH=11.82pH=13.20
1 St A id St B
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mL NaOH pH
0 0.30
10.0 0.44
49.0 2.17
50.0 7.00
51.0 11.82
80.0 13.22
1. StrongAcid - StrongBaseSummary: (NaOH is added to HCl)
Why does pH change drasticallynear equivalence point ()?
pH dependent on MOLESpresentAFTERreaction!
1 St A id St B
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At equivalencepoint: OHH
nn1
2
3
4
MOLESpresentAFTERreacting0.050
0.040
0.001
00
0
0
0
0
0
0.001
0.030
OHNaClNaOHHCl 2
1. StrongAcid - StrongBaseSummary: (NaOH is added to HCl)
StepmL
NaOH
n H+
(after rx n)
n OH-
(after rxn )
1 0
2 10.0
2 49.0
3 50.0
4 51.0
4 80.0
What does a
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What does aStrong Base-Strong Acid
Titration Look Like?
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Question: Where is the end point for the following titration
curve?
33
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pH at VariousTitration Points
2. Weak Acid
&
Strong Base
34
2 Weak Acid - Strong Base:
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A. Initial pH:beforeadding base
NoNaOH added, onlyHC2H3O2present
pH =acidic
35
A
)()((aq)(aq) 2232232 lOHaqOHCOHOHHC
2. WeakAcid - StrongBase:(NaOH added to HC2H3O2)
100mL0.50M
?mL0.10M
pH=2.52
2 Weak Acid - Strong Base:
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B. Beforeequivalence pt: HC2H3O2& NaOH react
Baselimiting
Acidexcess pH =slowlymore basic,
b/c less acid in excess
Raises rapidlynear
equivalence pt.
A BUFFER soln!
HC2H3O2& conjugate
base (C2H3O2-
) present 36
B
OHOHCOHOHHC 2232232
2. WeakAcid - StrongBase:(NaOH added to HC2H3O2)
100mL0.50M
?mL0.10M
pH=5.69
2 Weak Acid - Strong Base:
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C. At equivalencept: HC2H3O2 & NaOH react
Moles acid=Moles of base
NOT completely neutralized!!
Have conjugatebase (C2H3O2-)
pH > 7
37
C
)(OH)(OHHCO(l)H)(OHC 2322232 aqaqaq
OHOHCOHOHHC 2232232
2. WeakAcid - StrongBase:(NaOH added to HC2H3O2)
100mL0.50M
?mL0.10M
pH=9.25
2 Weak Acid - Strong Base:
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D. After equivalence pt: HC2H3O2 & NaOH react
Acidlimiting
Completely consumed Baseexcess
pH = gets more basic
D
OHOHCOHOHHC 2232232
2. WeakAcid - StrongBase:(NaOH added to HC2H3O2)
100mL0.50M
?mL0.10M
pH=11.82
pH=13.20
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0 20 40 60 80 1000
2
4
6
8
10
12
14
pH
Volume of NaOH added (mL)
Titration Curve
Comparisons1. Initial pH:
S/Sis lower, more acidic
DissociatescompletelymoreH+in soln
2. After Equivalence:
Curves are the same Amount of excess
OH-is the same
W. acid S. base
S. acid S. base
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0 20 40 60 80 1000
2
4
6
8
10
12
14
pH
Volume of NaOH added (mL)
Titration Curve
Comparisons3. @ Equivalence point:
S/Smore rapidrise
Volumeneeded is same
pHdifferent S/S = 7.00
W/S > 7
- b/c conjugate base
present
VNaOH(HAc) =VNaOH(HCl)
W. acid S. base
S. acid S. base
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0 20 40 60 80 1000
2
4
6
8
10
12
14
pH
Volume of NaOH added (mL)
Titration Curve
Comparisons4. Before Equivalence point:
W/Sis a bufferedsoln!
Acid& conjugate basepresent
TitrationComparison
(extra)
W. acid S. base
S. acid S. base
http://www.youtube.com/watch?v=xRVTdDrrtLchttp://www.youtube.com/watch?v=xRVTdDrrtLchttp://www.youtube.com/watch?v=xRVTdDrrtLchttp://www.youtube.com/watch?v=xRVTdDrrtLc8/12/2019 Chap 17 No Titrate Calc No Clicker(2)
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Titration Curve
Comparisons Differences morepronounced, the weakerthe acid
Weaker acids have more basicequivalence points
Can determine Kaof aweakacid from thetitration curve
In a bufferedsystem: AcidBase
pKpH a log
0apKpH
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Titration of
Polyprotic Acids Polyprotic acidcontains 1 or more ionizable H
atoms
Ex: H3PO3=
H2C4H4O6=
Ionization occurs 1 H atom at a time,thus multipleequivalence pts exist
Ex: H3PO3
43
3H+
2H+
H2PO3-(aq)
H2PO3-(aq) HPO32-(aq)
(aq)H(aq)POH 33
(aq)H
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Titrating w/Indicators How do you know what indicatorto use?
Ideallyit should change at/nearthe equivalence pt.
Since pH changes so fast here, as long indicator changesanywhere on rapid rise of titration curve, all is ok
44
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Titrating w/Indicators Are the following goodindicators for the titration
shown?
45
1. Phenolphthalein: 2. MethylRed:
Yes, change colorin rapid rise
No, doesnt change colorin rapid rise
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Titrating w/Indicators What if not given a picture diagram for color change?
Indicators are acids thus have a Ka
Indicators change color when pHof the system equalstheir pKa!
Want pKa of Indicator to be as close to pH of
endpoint/equivalence as possible 46
IndHHInd
Color 1 Color 2
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Questions:1. Which indicators would work for the titration shown?
47
Both,b/c on rapid decline
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Questions:2. A laboratory worker is titrating an unknown solution of a
weak acid with a strong base. Which indicator shouldthey choose given the following titration curve?
A. Pentamethoxy red: pKa = 1.8
B. Congo red: pKa = 4.0
C. Azolitmin: pKa = 6.5
D. Phenolphthalein: pKa = 9.0
E. Trinitrobenzoic acid: pKa = 12.7
48
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Solubility Equilibria Some ions when combined form insolublesalts
PrecipitationRxns (Chap 4, solubility Rules)
Saturated solutioncontains undissolvedsolute
However, somedoes dissolve (SLIGHTLY!)
49
PbI2
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Solubility Equilibria Solubility-Product Constant, Kspequilibrium
constant for a slightlysoluble(or nearlyinsoluble)
ioniccompound Degreeto which a solid is soluble in water
NOsolidsor liquidsin equilibrium expression!
Appendix D
50
)(2I)(Pb(s)PbI 22 aqaq
22
sp ]][I[PbK
5107.1 x
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Sample Problem If 0.0012 mols PbI2(s) dissolves in 1.0 L water, what is
its Kspvalue?
51
22 ]][[ IPbKsp0.0012M 0 0
2(0.0012)0.0012-0.0012
0M 0.0012M 0.0024M
2]0024.0][0012.0[spK
9
109.6
xKsp
I
C
E
)(2I)(Pb(s)PbI 22 aqaq
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Solubility vs.
Solubility Product, Ksp Solubilitygrams dissolved to form a saturated
solution Units = grams/L
Molar Solubilitymolesdissolved to form asaturatedsolution Units = mols/L
Kspequilibrium constant for ionic solid & itssaturatedsolution
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Sample Problem If the Kspof BaF2is 1.7x10
-6, calculate the molarsolubility.
22 ]][[ FBaKsp)(2)((s)2
2 aqFaqBaBaF
26]2][[107.1 xxx
364107.1 xx
Mxx
3
105.7
[Ba2+]
1:1 ratio of Ba2+:BaF2,molar solubility of BaCl2= 7.5x10
-3M
x 0 0
2(x)+x-x
0M x 2x
I
C
E
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Factors Affecting Solubility1. Common Ion EffectAdding a common ion
decreasesthe solubilityof the partially soluble salt
AKA Le ChteliersPrinciple
Adding BaCl2(Ba2+) or NaF (F-) shifts equilibrium
54
)(2)((s) 22 aqFaqBaBaF
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Sample Problem What is the molar solubility of BaF2in 0.15M NaF?
55
)(2)((s) 22 aqFaqBaBaF
0 0.15
x 2x
x 0.15+2x
22 ]][[ FBaKsp
6107.1 x
26]15.0][[107.1 xx
Mxx5
1056.7
I
C
E
2]215.0][[ xx x
-x
0M
small
Just BaCl2= 7.5x10-3M
Decreased
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Factors Affecting Solubility2. pH:Almostany ioniccompound will dissolve if the
pH of the solution is altered
Solubilityincreasesif acidis added to a basicanion
Ex: Add HNO3to BaF2: H+from HNO3reacts w/F
-from BaF2
Adding more acid (H+) shifts equilibrium
56
)(aqH )( aqF )(aqHF22 2
)(2)((aq)2)(2
2 aqHFaqBaHsBaF
)(2)((s) 22 aqFaqBaBaF
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Factors Affecting SolubilityComplexes
3. In the presence of suitable Lewis bases, metalionscan form complexes:
57
(aq)S(aq)FeFeS(s) 22
(aq)CNFe(aq)6CN(aq)Fe -462
Ksp= 6.31x10-18
Kf= 1.00x1035
(aq)S(aq)CNFe(aq)6CNFeS(s)-2-4
6
K = 6.31x10
17
f for formation(of a complex).
More in Chapter 23, but will use this idea in Experiment 19!
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Precipitation &Separation of Ions
How do you know if a precipitatewill form?
Need to compare Kspto your actualconditions Qsp
IF:
Qsp= Ksp: Equilibrium (saturated soln)
Qsp> Ksp: Pptoccurs
Qsp< Ksp: Dissolutionoccurs
58
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Sample Problems
1. [Ca2+] in human blood is 0.0025M & Calcium oxalate (CaC2O4)makes kidney stones. If Ksp= 2.3x10
-9for calcium oxalate,will it ppt in a patient with [C2O4
-2] = 1.0x10-6?
59
]][[ 2422
OCCaQsp
]100.1][0025.0[ 6 xQsp9105.2 xQsp
Qsp> Ksp
Not at equilibrium, use Qsp
Ppt occurs & Kidney stones form (OUCH!!)
Sample exercises (in book)17.15 & 17.16
very helpful!
)()((s)2
42
2
42 aqOCaqCaOCaC
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Sample Problems
2. A solution contains 1.0x10-2M Ag+& 2.0x10-2M Pb2+.When Cl-is added, both AgCl (Ksp=1.8x10
-10) & PbCl2(Ksp=1.7x10
-5) can precipitate. Which precipitates first?
60
]][[ ClAgKsp22 ]][[ ClPbKsp
Solve for [Cl-]
10108.1 x
8108.1][
xCl
225 ]][100.2[107.1 Clxx2
109.2][
xClAnything abovethis will ppt
AgCl ppt first, b/c smaller [Cl-]
]][100.1[ 2 Clx
Anything abovethis will ppt
ua tat ve Ana ys s
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Determines presenceorabsenceof metalions
Noinfo about amount
5 groups
1. Insoluble Cl-
2. InsolubleAcid S-
3. Insoluble Base S-&OH-
4. Insoluble PO4-3
5. Soluble alkali metal& NH4
+ions
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y(selective precipitation)
(LAB 22)
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Sample Question
1. Which ion will precipitate whenphosphate ion is added to a
solution containing all of theions below
A. K+
B. Ba2+
C. Na+
D. NH4+
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Summary Chap. 17
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Summary Chap. 171. Common Ion Effect
2. Buffers:
Calculationsa) Ice Table
b) Henderson-Hasselbalch eq.
3. Adding Strong Acid or Base to a buffer
RXN occurs! ICE table (MOLES)
H-H eq. (M)
4. Acid/Base Titration
S/S
S/W
Compare titration curves
5. Solubility equilibria
6. Qualitative analysis
acidbasepKpH a log