SKOOG - SOLUCIONÁRIO CAPÍTULO 17

Prévia do material em texto

Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
Chapter 17
17-1 (a) A chelate is a cyclic complex consisting of metal ion and a reagent that contains two
or more electron donor groups located in such a position that they can bond with the
metal ion to form a Heterocyclic ring structure.
(b) A tetradentate chelating agent is a molecule that contains four pairs of donor electron
located in such positions that they all can bond to a metal ion, thus forming two rings.
(c) A ligand is a species that contains one or more electron pair donor groups that tend to
form bonds with metal ions.
(d) The coordination number is the number of covalent bonds that a cation tends to form
with electron donor groups.
(e) A conditional formation constant is an equilibrium constant for the reaction between a
metal ion and a complexing agent that applies only when the pH and/or the concentration
of other complexing ions are carefully specified.
(f) NTA is the acronym for nitrilotriacetic acid, a tetradentate complexing agent that
contains three carboxylate groups and one tertiary amine. As an electron donor, NTA has
found applications in the titration of a variety of cations.
(g) Water hardness is the concentration of calcium carbonate that is equivalent to the
total concentration of all of the multivalent metal carbonates in the water.
(h) In an EDTA displacement titration, an unmeasured excess of a solution containing the
magnesium or zinc complex of EDTA is introduced into the solution of an analyte that
forms a more stable complex that that of magnesium or zinc. The liberated magnesium
or zinc ions are then titrated with a standard solution of EDTA. Displacement titrations
are used for the determination of cations for which no good indicator exists.
Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
17-2 Three general methods for performing EDTA titrations are (1) direct titration, (2) back
titration, and (3) displacement titration. Method (1) is simple, rapid, but requires one
standard reagent. Method (2) is advantageous for those metals that react so slowly with
EDTA as to make direct titration inconvenient. In addition, this procedure is useful for
cations for which satisfactory indicators are not available. Finally, it is useful for
analyzing samples that contain anions that form sparingly soluble precipitates with the
analyte under analytical conditions. Method (3) is particularly useful in situations where
no satisfactory indicators are available for direct titration.
17-3 Multidentate ligands offer the advantage that they usually form more stable complexes
than do unidentate ligands. Furthermore, they often form but a single complex with the
cation, which simplifies their titration curves and makes end-point detection easier.
17-4 (a)
]CN][)CN(Ni[
])CN(Ni[
)CN(NiCN)CN(Ni
]CN][)CN(Ni[
])CN(Ni[
)CN(NiCN)CN(Ni
]CN][)CN(Ni[
])CN(Ni[
)CN(NiCN)CN(Ni
]CN][Ni[
])CN(Ni[
)CN(NiCNNi
3
2
4
4
2
43
2
3
332
2
22
21
2





















K
K
K
K
Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
(b)
]SCN][)SCN(Cd[
])SCN(Cd[
)SCN(CdSCN)SCN(Cd
]SCN][)SCN(Cd[
])SCN(Cd[
)SCN(CdSCN)SCN(Cd
]SCN][Cd[
])SCN(Cd[
)SCN(CdSCNCd
2
3
332
2
22
21
2















K
K
K
17-5 (a) hexaaminezinc(II), Zn(NH3)62+
(b) dichloroargentate, Ag(Cl)2-
(c) disulfatocuprate(II), Cu(SO4)22-
(d) trioxalotoferrate(III), Fe(C2O4)33-
(e) hexacyanoferrate(II), Fe(CN)64-
17-6 The overall formation constantn is equal to the product of the individual stepwise
constants. Thus, the overall constant for formation of Cd(SCN)3- in Question 17-4(b) is
32
3
3213 ]SCN][Cd[
])SCN(Cd[


 KKK
which is the equilibrium constant for the reaction


 32 )SCN(CdSCN3Cd
and
22
2
212 ]SCN][Cd[
])SCN(Cd[
 KK
where the overall constant2 is for the equation
2
2 )SCN(CdSCN2Cd


Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
17-7 (a) acetate (1)
a
a
a
a
3
3
T
3
1
a
a
3
a
33
a
3
T
a
3
3
3
3
a33T
33
]H[]H[
]COOCH[
]COOCH[]COOCH[
]H[
]COOCH[1
]H[
]COOCH[]COOCH[
]H][COOCH[
]H][COOCH[
]COOHCH[
]COOHCH[
]H][COOCH[
]COOCH[]COOHCH[
HCOOCHCOOHCH
K
K
K
Kc
K
K
KK
c
K
Kc





 




 


 

















(b) tartrate (2)
2a1a
2
2242
1a
242
2242
2a
2242
242
242
2242
2a2242242
2242
242
1a2422242
]H][)COO(OHC[]H)][COO)(COOH(OHC[
)COOH(OHC[
]H][)COO(OHC[
)COO)(COOH(OHC[
)]COO)(COOH(OHC[
]H][)COO(OHC[
H)COO(OHC)COO)(COOH(OHC
])COOH(OHC[
]H)][COO)(COOH(OHC[
H)COO)(COOH(OHC)COOH(OHC
KKK
K
K
K
















2a1a1a
2
2a1a
2a1a
2a1a1a
2
2242
2242
T
2242
2
2a1a
2a1a1a
2
2242
2a2a1a
2
2242
2242
2a
2242
2a1a
2
2242
22422422242T
]H[]H[]H[]H[
])COO(OHC[
])COO(OHC[
])COO(OHC[
]H[]H[
])COO(OHC[1
]H[]H[
])COO(OHC[
])COO(OHC[
]H][)COO(OHC[]H][)COO(OHC[
])COO(OHC[)]COO)(COOH(OHC[])COOH(OHC[
KKK
KK
KK
KKK
c
KK
KKK
KKK
KKK
c





 





 


 













Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
(c) phosphate (3)
3a2a1a
33
4
1a
42
43
3a2a
23
4
2a
2
4
42
3a
3
42
4
2
4
3
4
3a
3
4
2
4
42
2
4
2a
2
442
43
42
1a4243
]H][PO[]H][POH[
]POH[
]H][PO[]H][HPO[
]POH[
]H][PO[
]HPO[
]HPO[
]H][PO[
HPOHPO
]POH[
]H][HPO[
HHPOPOH
]POH[
]H][POH[
HPOHPOH
KKKK
KKK
K
K
K
K

























3a2a1a2a1a
2
1a
3
3a2a1a
3a2a1a
2a2a1a2a1a
2
1a
3
3
4
3
4
T
3
4
3
3a2a1a
2a2a1a2a1a
2
1a
3
3
4
3a3a2a
2
3a2a1a
3
3
4
3
4
3a
3
4
3a2a
23
4
3a2a1a
33
4
3
4
2
44243T
]H[]H[]H[
]H[]H[]H[
]PO[
]PO[]PO[
]H[]H[]H[
]PO[
1
]H[]H[]H[
]PO[
]PO[
]H][PO[]H][PO[]H][PO[
]PO[]HPO[]POH[]POH[
KKKKKK
KKK
KKK
KKKKKKc
KKK
KKKKKK
KKKKKK
KKKKKK
c





 




 



 













17-8 (a)
T
3
2
3
)COOCH(Fe1)COOCH(Fe
'
T1
3
2
3
3
3
2
3
)COOCH(Fe
2
33
3
]Fe[
])COOCH(Fe[
]Fe[
])COOCH(Fe[
]COOCH][Fe[
])COOCH(Fe[
)COOCH(FeCOOCHFe
2
3
2
3
2
3
c
KK
c
K















Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
(b)
T
3
2242
))COO(OHC(Fe2))COO(OHC(Fe
'
T2
3
2242
2242
3
2242
))COO(OHC(Fe
22422242
3
]Fe[
]))COO(OHC(Fe[
]Fe[
]))COO(OHC(Fe[
])COO(OHC][Fe[
]))COO(OHC(Fe[
))COO(OHC(Fe)COO(OHCFe
2242
2242
2242
c
KK
c
K
















(c)
T
3
4
FePO3FePO
'
T3
3
4
3
4
3
4
FePO4
3
4
3
]Fe[
]FePO[
]Fe[
]FePO[
]PO][Fe[
]FePO[
FePOPOFe
44
4
c
KK
c
K






17-9
T2
2
T
2
2
3
3
23
T
3
3
3
3
T23
3
3
323
3
3'
3
3
3
23
]Ox[
]Ox[
)(
)](Fe[
])Ox(Fe[
)](Fe[
])Ox(Fe[
]Ox][Fe[
])Ox(Fe[
)Ox(FeOx3Fe
c
c
cc















17-10 Titrate the three ions in an aliquot of the sample that has been buffered to a pH of about
10. Buffer a second aliquot to a pH of about 4 and titrate the zinc and indium ions.
Finally, titrate an aliquot that has been brought to a pH of about 1.5. Only the indium is
complexed under these conditions.
17-11
]Llog[n]Mlog[]MLlog[log
equationtheofsidesbothofrithmgalotheTake
]L][M[
]ML[
nn
n
n
n


Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
Now, write the right side of the equation as a pfunction (i.e., p[M] = -log[M])
nn pMLnpLpMlog 
17-12 The MgY2- is added to assure a sufficient analytical concentration of Mg2+ to provide a
sharp end point with Eriochrome Black T indicator.
17-13
EDTAM00845.0
L000.1
OH2YHNag24.372
EDTAmole1
reagentg100
OH2YHNag7.99
reagentg156.3
222
222


17-14
EDTAM007010.0
EDTAmL22.32
Mgmmol
EDTAmmol1
mL
Mgmmol004517.0
mL00.50 2
2

 

17-15 (a)
EDTAmL25.40
mmol0500.0
EDTAmL1
)NO(Mgmmol
EDTAmmol1
)NO(MgmL16.27
mL
)NO(Mgmmol0741.0
23
23
23


(b)
EDTAmL42.39
mmol0500.0
EDTAmL1
CaCOmmol
EDTAmmol1
g09.100
CaCOmmol1000
CaCOg1973.0
3
3
3 
Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
(c)
EDTAmL63.48
mmol0500.0
EDTAmL1
OH2CaHPOmmol
EDTAmmol1
OH2CaHPOmmol43123.2
OH2CaHPOmmol43123.2
g09.172
OH2CaHPOmmol1000
sampleg100
OH2CaHPOg4.81
sampleg5140.0
24
24
24
2424





(d)
EDTAmL66.48
mmol0500.0
EDTAmL1
OH3)OH(MgMgCO3mmol
EDTAmmol4
g3.365
OH3)OH(MgMgCO3mmol1000
OH3)OH(MgMgCO3g2222.0
223
223
223



(e)
EDTAmL37.28
mmol0500.0
EDTAmL1
MgCOCaCOmmol
EDTAmmol2
g4.184
MgCOCaCOmmol1000
sampleg100
MgCOCaCOg5.92
sampleg1414.0
33
3333



17-16 First calculate the CoSO4 concentration,
4
44 CoSOM01093.0
mg0.155
CoSOmmol1
mL
CoSOmg694.1 
In each part,
44 CoSOmmol2732.0mL00.25mL
mmol01093.0
CoSOmmol 
(a)
EDTAmL62.31
mmol008640.0
EDTAmL1
CoSOmmol
EDTAmmol1
CoSOmmol2732.0
4
4 
Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
(b)
EDTAmmol1588.0
CoSOmmol
EDTAmmol1
CoSOmmol2732.0
mL00.50
mL
EDTAmmol008640.0
EDTAexcessmmol
4
4 


 




 


 2
22
ZnmL80.16
mmol009450.0
ZnmL1
EDTAmmol
Znmmol1
EDTAmmol1588.0
(c)
EDTAmL62.31
mmol008640.0
EDTAmL1
Znmmol
EDTAmmol1
CoSOmmol
Znmmol1
CoSOmmol2732.0 2
4
2
4  

17-17







 
2
22
Zn%195.3
%100
sampleg7162.0
mmol1000
Zng39.65
EDTAmmol
Znmmol1
EDTAmL27.21
mL
EDTAmmol01645.0
17-18
  22
2
2
2
cm
Crmg
998.0
cm00.400.3
mmol
Crmg996.51
EDTAmmol
Crmmol1
EDTAmmol2303.0
EDTAmmol2303.0
Cummol
EDTAmmol1
CumL30.4
mL
Cummol008120.0
EDTAmL00.15
mL
EDTAmmol01768.0
reactedEDTAmmol





 



 




 



Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
17-19
42
4242
SOTl%228.1
%100
sampleg76.9
mmol1000
SOTlg8.504
EDTAmmol2
SOTlmmol1
EDTAmL34.13
mL
EDTAmmol03560.0





 
17-20 (a)
EDTAM01076.0
EDTAmL35.42
MgCOmmol
EDTAmmol1
MgCOmL0.50
g314.84
MgCOmmol1000
mL1000
MgCOg7682.0
3
3
33




 
(b)
 
M10094.8
mL00.25
mL81.18
mL
mmol10076.1
samplemL
MgCOmmolCaCOmmol 3
2
33 





 

3
633
3
3333
3
3
2
3
CaCOppm2.679
ppm10
sampleg
samplemL000.1
mmol1000
CaCOg09.100
samplemL
CaCOmmol10786.6
M10308.1M10786.6M10094.8
samplemL
MgCOmmol
M10786.6
mL00.50
EDTAmmol
CaCOmmol1
EDTAmL54.31
mL
EDTAmmol10076.1
samplemL
CaCOmmol







 





(c)
3
633
3
MgCOppm3.110
ppm10
sampleg
samplemL000.1
mmol1000
MgCOg314.84
samplemL
MgCOmmol10308.1



Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
17-21
 

















 





 



2
2
2
3
3
3
2
2
2
3
3
3
Feppm0.213
mL1000
L
mL00.50
mmol
Femg847.55
Femmol19068.0
Feppm0.184
mL1000
L
mL00.50
mmol
Femg847.55
Femmol16476.0
Femmol19068.0
EDTAmmol
Femmol1
EDTAmL73.1362.29
mL
EDTAmmol01200.0
Femmol
Femmol16476.0
EDTAmmol
Femmol1
EDTAmL73.13
mL
EDTAmmol01200.0
Femmol
17-22










22
2
2
2
22
22
Mgmmol059835.0048352.0108187.0Mgmmol
Cammol048352.0
EDTAmmol
Cammol1
EDTAmL21.12
mL
EDTAmmol003960.0
Cammol
mmol108187.0
EDTAmmol
CammolMgmmol
EDTAmL32.27
mL
EDTAmmol003960.0
CammolMgmmol











 





 
2
2
2
2
2
2
Mgppm9.290
L000.2
1
mL1000
L
mL00.10
mmol
Mgmg305.24
Mgmmol059835.0
Cappm6.387
L000.2
1
mL1000
L
mL00.10
mmol
Camg08.40
Cammol048352.0
Both values are within normal limits.
Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
17-23

















 





 




2
2
2
2
2
2
22
2
2
2
22
22
Cd%86.44%100
mL0.250
mL00.50
sampleg509.1
mmol1000
Cdg41.112
Cdmmol204.1
Pb%16.55%100
mL0.250
mL00.50
sampleg509.1
mmol1000
Pbg2.207
Pbmmol80342.0
Cdmmol20444.1mmol80342.0mmol00786.2Cdmmol
Pbmmol80342.0
EDTAmmol
Pbmmol1
EDTAmL56.11
mL
EDTAmmol06950.0
Pbmmol
mmol00786.2
EDTAmmol
PbmmolCdmmol
EDTAmL89.28
mL
EDTAmmol06950.0
PbmmolCdmmol
17-24













22
2
2
2
2
2
2
22
22
Nimmol76718.0mmol65388.1mmol42106.2Nimmol
Cummol65388.1
gmmol
Cummol1
MgmL85.22
mL
Mgmmol07238.0
Cummol
mmol42106.2
EDTAmmol
CummolNimmol
EDTAmL81.45
mL
EDTAmmol05285.0
CummolNimmol











 





 
2
2
2
2
2
2
Cu%02.70%100
mL0.100
mL00.25
sampleg6004.0
mmol1000
Cug546.63
Cummol65388.1
Ni%00.30%100
mL0.100
mL00.25
sampleg6004.0
mmol1000
Nig693.58
Nimmol76718.0
Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
17-25
32
32
2
322
2
OFe%256.0
%100
mL0.250
mL00.50
sampleg022.1
mmol1000
OFeg69.159
ZnYmmol2
OFemmol1
ZnYmL40.2
mL
ZnYmmol002727.0
ZnO%7.99
%100
mL0.250
mL00.10
sampleg022.1
mmol1000
ZnOg39.81
EDTAmmol
ZnOmmol1
EDTAmL71.38
mL
EDTAmmol01294.0






 






 



17-26 1 mmol EDTA1 mmol Ni2+2 mmol NaBr2 mmol NaBrO3
For the 10.00 mL aliquot,
 
M09166.0
mL00.10
EDTAmmol
NaBrOmmolNaBrmmol2
EDTAmL94.21
mL
EDTAmmol02089.0
solutionsamplemL
NaBrOmmolNBrmmol
3
3




 

For the 25.00 mL aliquot,
3
3 NaBrOM04699.004467.009166.0
solutionsamplemL
NaBrOmmol
NaBrM04467.0
mL00.25
EDTAmmol
NaBrmmol2
EDTAmL73.26
mL
EDTAmmol02089.0
solutionsamplemL
NaBrmmol





 

Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
3
33NaBrO%57.48%100
sampleg650.3
mmol1000
NaBrOg9.150
mL0.250
mL
NaBrOmmol04699.0
NaBr%48.31%100
sampleg650.3
mmol1000
NaBrg9.102
mL0.250
mL
NaBrmmol04467.0




 




 
17-27 1 mmol Mg2+1 mmol EDTA¼ mmol B(C6H5)4-¼ K+











 
Kppm68.64
mL1000
L
mL250
mmol
Kmg098.39
Mgmmol4
Kmmol1
MgmL64.29
mL
Mgmmol05581.0
2
2
2
17-28
mmol3604.11
mL0.250
mL00.50
mmol27208.2
CrFeNimmolmL0.350inreactedEDTAmmol
mmol27208.2
Cummol
EDTAmmol1
CumL11.5
mL
Cummol06241.0
EDTAmL00.50
mL
EDTAmmol05182.0
mL00.50inreactedEDTAmmol
2
2
2




 




 



Nimmol7133.6
mL0.250
mL00.50
EDTAmmol
Nimmol1
EDTAmL91.25
mL
EDTAmmol05182.0
Nimmol
Nimmol9603.1mmol4002.9mmol3604.11Crmmol
mmol4002.9
mL0.250
mL00.50
EDTAmL28.36
mL
EDTAmmol05182.0
FemmolNimmol




 







 

Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
Fe%19.23%100
g6472.0
mmol1000
Feg847.55
Femmol6869.2
Fe%
Ni%88.60%100
g6472.0
mmol1000
Nig69.58
Nimmol7133.6
Ni%
Cr%75.15%100
g6472.0
mmol1000
Crg996.51
Crmmol9603.1
Cr%
Femmol6869.2mmol7133.6mmol4002.9Femmol










17-29
Pbmmol1350.0
mL0.500
mL0.100
EDTAmmol
Pbmmol1
EDTAmL80.10
mL
EDTA002500.0
Pbmmol
Cummol3115.3mmol3835.1mmol6950.4Cummol
mmol3835.1
mL0.500
mL00.25
EDTAmL67.27
mL
EDTAmmol002500.0
ZnmmolPbmmol
mmol6950.4
mL0.500
mL00.10
EDTAmL56.37
mL
EDTAmmol002500.0
CuZnPbmmolEDTAmmol




 







 






 

Cu%08.64%100
g3284.0
mmol1000
Cug55.63
Cummol3115.3
Cu%
Znmmol2485.1mmol1350.0mmol3835.1Znmmol




Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
Sn%54.2)%87.24518.807.64(%100Sn%
Zn%86.24%100
g3284.0
mmol1000
Zng39.65
Znmmol2485.1
Zn%
Pb%518.8%100
g3284.0
mmol1000
Pbg2.207
Pbmmol1350.0
Pb%







17-30
A B C D E F G H
1 17-30 Conditional constants for Fe2+- EDTA complex
2 Note: The conditional constant K'MY is the product of4 and KMY (Equation 17-25).
3 The value of KMY is found in Table 17-3.
4 KMY 2.10E+14 pH D 4 K'MY
5 K1 1.02E-02 6.0 3.69E-17 2.25E-05 4.7E+09 Note that Excel does not
6 K2 2.14E-03 8.0 1.54E-19 5.39E-03 1.1E+12 follow the rounding rules
7 K3 6.92E-07 10.0 2.34E-21 3.55E-01 7.5E+13 developed in Section 6D-3.
8 K4 5.50E-11
9 Spreadsheet Documentation
10 D5=(10^-C5)^4+$B$5*(10^-C5)^3+$B$5*$B$6*(10^-C5)^2+$B$5*$B$6*$B$7*(10^-C5)+$B$5*$B$6*$B$7*$B$8
11 E5=$B$5*$B$6*$B$7*$B$8/D5
12 F5=E5*$B$4
Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
17-31
A B C D E F G H I
1 17-31 Conditional constants for Ba2+- EDTA complex
2 Note: The conditional constant K'MY is the product of4 and KMY (Equation 17-25).
3 The value of KMY is found in Table 17-3
4 KMY 5.80E+07 pH D 4 K'MY
5 K1 1.02E-02 7.0 1.73E-18 4.80E-04 2.8E+04
6 K2 2.14E-03 9.0 1.60E-20 5.21E-02 3.0E+06
7 K3 6.92E-07 11.0 9.82E-22 8.46E-01 4.9E+07
8 K4 5.50E-11
9 Spreadsheet Documentation
10 D5=(10^-C5)^4+$B$5*(10^-C5)^3+$B$5*$B$6*(10^-C5)^2+$B$5*$B$6*$B$7*(10^-C5)+$B$5*$B$6*$B$7*$B$8
11 E5=$B$5*$B$6*$B$7*$B$8/D5
12 F5==E5*$B$4
Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
17-32
A B C D E F G H
1 17-32 Titration of 50.00 mL of 0.01000 M Sr2+with 0.02000 M EDTA
2 Note: The conditional constant K'MY is the product of4 and KMY (Equation 17-25).
3 The value of KMY is found in Table 17-3.
4 KMY 4.30E+08 pH D 4 K'MY
5 EDTA K1 1.02E-02 11.0 9.82E-22 8.46E-01 3.64E+08
6 K2 2.14E-03
7 K3 6.92E-07
8 K4 5.50E-11
9 Initial conc. Sr2+ 0.01000 Initial Vol. 50.00
10 Initial conc. EDTA 0.02000
11 Vol. EDTA, mL cSr2+ cSrY2- cT [Sr
2+] [SrY2-] pSr
12 0.00 0.01000 0 0.01000 2.00
13 10.00 0.00500 0.00333 0.00500 2.30
14 24.00 0.00027 0.00649 0.00027 3.57
15 24.90 0.00003 0.00665 0.00003 4.57
16 25.00 0.00000 0.00667 0.00667 4.28E-06 0.00667 5.37
17 25.10 0.00666 2.66E-05 6.87E-07 0.00666 6.16
18 26.00 0.00658 2.63E-04 6.87E-08 0.00658 7.16
19 30.00 0.00625 1.25E-03 1.37E-08 0.00625 7.86
20 Spreadsheet Documentation
21 B12=($B$9*$D$9-$B$10*A12)/($D$9+A12)
22 C12=($B$10*A12)/($D$9+A12)
23 C16=($B$10*$A$16)/($D$9+A16)
24 D17=($B$10*A17-$D$9*$B$9)/($D$9+A17)
25 D16=($B$10*$A$16)/($D$9+A16)
26 E12=B12
27 E16=SQRT(C16/$F$5)
28 E17=C17/(D17*$F$5)
29 F16=C16
30 H12=-LOG10(E12)
31
32
33
34
35
36
37
38
39
Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
17-33
A B C D E F G H
1 17-33 Titration of 50.00 mL of 0.0150 M Fe2+with 0.0300 M EDTA
2 Note: The conditional constant K'MY is the product of4 and KMY (Equation 17-25).
3 The value of KMY is found in Table 17-3.
4 KMY 2.10E+14 pH D 4 K'MY
5 EDTA K1 1.02E-02 7.0 1.73E-18 4.80E-04 1.01E+11
6 K2 2.14E-03
7 K3 6.92E-07
8 K4 5.50E-11
9 Initial conc. Fe2+ 0.0150 Initial Vol. 50.00
10 Initial conc. EDTA 0.0300
11 Vol. EDTA, mL cFe2+ cFeY2- cT [Fe
2+] [FeY2-] pFe
12 0.00 0.01500 0 0.01500 1.82
13 10.00 0.00750 0.00500 0.00750 2.12
14 24.00 0.00041 0.00973 0.00041 3.39
15 24.90 0.00004 0.00997 0.00004 4.40
16 25.00 0.00000 0.01000 0.01000 3.15E-07 0.01000 6.50
17 25.10 0.00999 3.99E-05 2.48E-09 0.00999 8.61
18 26.00 0.00987 3.95E-04 2.48E-10 0.00987 9.61
19 30.00 0.009375 1.88E-03 4.96E-11 0.00938 10.30
20 Spreadsheet Documentation
21 B12=($B$9*$D$9-$B$10*A12)/($D$9+A12)
22 C12=($B$10*A12)/($D$9+A12) Note: The method is identical to Problem
23 C16=($B$10*$A$16)/($D$9+A16) 17-32.
24 D17=($B$10*A17-$D$9*$B$9)/($D$9+A17)
25 D16=($B$10*$A$16)/($D$9+A16)
26 E12=B12
27 E16=SQRT(C16/$F$5)
28 E17=C17/(D17*$F$5)
29 F16=C16
30 H12=-LOG10(E12)
31
32
33
34
35
36
37
38
39
Fundamentals of Analytical Chemistry: 8th ed. Chapter 17
17-34









 




 
22
2
2
2
22
Mgmmol1099.01751.02850.0Mgmmol
Cammol1751.0
EDTAmmol
Cammol1
EDTAmL53.14
mL
EDTAmmol01205.0
Cammol
mmol2850.0EDTAmL65.23
mL
EDTAmmol01205.0
MgmmolCammol
(a)
See discussion of water hardness in 17D-9.
3
3
22
3
CaCOppm5.570
mL1000
L
mL00.50
mmol
CaCOmg087.100
mmol2850.0
MgCappmCaCOppmhardnessWater



 
(b)
3
3
2
32
CaCOppm5.350
mL1000
L
mL00.50
mmol
CaCOmg08.100
Cammol
CaCOmmol1
Cammol1751.0





  

(c)
3
3
2
32
MgCOppm3.185
mL1000
L
mL00.50
mmol
MgCOmg30.84
Mgmmol
MgCOmmol1
Mgmmol1099.0





  
