Néher-Neumann Advanced Potentiometry

Potentiometric Titrations and Their Systematic Errors
2009
ISBN: 978-1-4020-9525-2
Verlag: Springer Netherlands
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 350 Seiten

'Advanced Potentiometry' details the accurate calculation of potentiometric titrations. Additional terms such as the ideal diffusion potential together with the contribution of activity factors furnish calculated stability constants which do not include systematic errors and thus present a complete and correct description of equilibrium processes. Moreover, serious systematic errors resulting from the recent use of curve-fitting computer programs are highlighted later in the text. 'Advanced Potentiometry' can advantageously be used by lecturers, researchers, PhD graduates and undergraduate students working in the fields of Solution Chemistry, Physical Chemistry, Inorganic Chemistry and Analytical Chemistry and Environmental Research.

Autoren/Hrsg.

Néher-Neumann, Erzsébet

Inhaltsverzeichnis

1;Contents;6
2;List of Definitions and Symbols;10
3;Preface;14
4;References;16
5;Acknowledgement;18
6;to 1 Introduction ;19
6.1;1.1 The Titration of Weak Acids (HL, H 3 L) with a Strong Base;19
6.2;1.2 The Measurement of the Concentration of the H + or the Metal Ion B z(B)+ by Means of an Emf Cell;20
6.2.1;1.2.1 The Total Emf of Cell B;21
6.2.2;1.2.2 The Total Emf of Cell H;25
6.2.3;1.2.3 The Constant Ionic Medium Method;28
6.3;1.3 On the Curve-Fitting Computer Treatment [2d];29
6.4;1.4 On the Deduction of Theoretical Equations;31
7;to 2 Emf Cells with Mixtures of Strong Electrolytes and Liquid Junctions of the Type AY | AY + HY + BYz(B);35
7.1;2.1 Studies on Emf Cells Where [A + ] = C M, Constant [1];35
7.1.1;2.1.1 Cell B Using an Amalgam/Ion-Selective Indicator Electrode;36
7.1.1.1;2.1.1.1 The Determination of E 0B and Some Slope Functions;36
7.1.1.2;2.1.1.2 The Estimation of the Systematic Errors in the Equilibrium Constants, 0 log 10 0 pqr , Caused by the Use of the Conditional Experimental Constant E 0B1 ;40
7.1.2;2.1.2 Cell H Using a Glass Indicator Electrode;41
7.1.2.1;2.1.2.1 The Determination of E 0H and Some Slope Functions;41
7.1.2.2;2.1.2.2 The Estimation of the Systematic Errors in the Equilibrium Constant, 0 log 10 0 pqr , Caused by the Use of the Conditional Experimental Constant E 0H1 ;45
7.2;2.2 Studies on Emf Cells Where [Y ] = C M, Constant [1];46
7.2.1;2.2.1 Cell B Using an Amalgam/Ion-Selective Indicator Electrode;47
7.2.1.1;2.2.1.1 The Determination of E 0B and Some Slope Functions;47
7.2.1.2;2.2.1.2 The Estimation of the Systematic Errors in the Equilibrium Constant, 0 log 10 0 pqr , Caused by the Use of the Conditional Experimental Constant E 0B1 ;49
7.2.2;2.2.2 Emf Studies in Cell H Using a Glass Indicator Electrode;50
7.2.2.1;2.2.2.1 The Determination of the Constant E 0H and Some Slope Functions;50
7.2.2.2;2.2.2.2 The Estimation of the Systematic Errors in the Equilibrium Constants, 0 log 10 0 pqr , Caused by the Use of the Conditional Constant E 0H1 ;52
7.3;2.3 Studies on Emf Cells Where the Ionic Strength (I) = C M, Constant [1];52
7.3.1;2.3.1 Emf Studies in Cell B Using an Amalgam Indicator Electrode;54
7.3.1.1;2.3.1.1 The Determination of E 0B and Some Slope Functions;54
7.3.1.2;2.3.1.2 The Estimation of the Systematic Errors in the Equilibrium Constants, 0 log 10 0 pqr , Caused by the Use of the Conditional Constant E 0B1 ;55
7.3.2;2.3.2 Emf Studies in Cell H Using a Glass Indicator Electrode;55
7.3.2.1;2.3.2.1 The Determination of E 0H and Some Slope Functions;56
7.3.2.2;2.3.2.2 The Estimation of the Systematic Errors in the Equilibrium Constants, 0 log 10 0 pqr , Caused by the Use of the Conditional Constant E 0H1 ;57
7.4;2.4 Conclusion on Emf Studies of Mixtures of Strong Electrolytes;57
8;to 3 Determination of the Ionic Molar Conductivities in Mixtures of the Strong Electrolytes HClO4 + NaClO4 + Cd(ClO4)2;65
8.1;3.1 Introduction;65
8.2;3.2 Conductivity Measurements;66
8.2.1;3.2.1 Conductivity Measurements in Mixtures Where [Na + ] = 30M, Constant [ 1 ];66
8.2.1.1;3.2.1.1 Conductivity Measurements in Mixture 1 Where c B is Varied While c H is Kept Constant;66
8.2.1.2;3.2.1.2 Conductivity Measurements in Mixture 2 Where c H is Varied While c B is Kept Constant;70
8.2.1.3;3.2.1.3 Conductivity Measurements in Mixture 3 Where Both c B and c H Are Varied;73
8.2.1.4;3.2.1.4 Conclusion Which Can Be Obtained from Tables 2.2 and 3.1 ;73
8.2.1.5;3.2.1.5 Measurement of the Molar Conductivity of Concentrated Aqueous Cd(ClO 4 ) 2 Solutions;74
8.2.2;3.2.2 Conductivity Measurements in Mixtures Where [ClO 4 0 ] = 30M, Constant [ 7 ];75
8.2.2.1;3.2.2.1 Conductivity Measurements in Mixture 2 Where c H Is Varied While c B Is Kept Constant;76
8.2.2.2;3.2.2.2 Conductivity Measurements in Mixture 1 Where c B Is Varied While c H Is Kept Constant;79
8.2.2.3;3.2.2.3 Conductivity Measurements in Mixture 3 Where Both c B and c H Are Varied;83
8.2.3;3.2.3 Conductivity Measurements in Mixtures Where I = C M, Constant [ 8 ];84
8.2.3.1;3.2.3.1 Conductivity Measurements in Mixture 1 Where c B Is Varied While c H Is Kept Constant;84
8.2.3.2;3.2.3.2 Conductivity Measurements in Mixture 2 Where c H Is Varied While c B Is Kept Constant;88
8.2.3.3;3.2.3.3 Conductivity Measurements in Mixture 3 Where Both c B and c H Are Varied;91
8.3;3.3 Conclusion on Conductivity Measurements;91
8.4;3.4 Experimental Details;93
9;to 4 Studies on Emf Cells Where Complex Formation Takes Place Using Liquid Junctions of the Type AY AY + HY + BYz(B) + AyL and -- log10 [H+] 7;95
9.1;4.1 Deduction of the General Equations [ 1 ];95
9.1.1;4.1.1 Introduction;95
9.1.2;4.1.2 Definitions and Symbols Used in Equilibrium Systems;96
9.1.3;4.1.3 Deduction of the Potential Functions E D , E Df , E B and E H ;99
9.1.4;4.1.4 Calculation of the Ideal Diffusion Potential, E D, in Cells with Complex Formation;100
9.1.5;4.1.5 The Suggested Function for E D for the Preliminary Treatment of Emf Data;102
9.1.6;4.1.6 Calculation of the Contribution of the Activity Coefficients to the Ideal Diffusion Potential, E Df , in Cells with Complex Formation;103
9.1.7;4.1.7 The Suggested Function for E Df for the Preliminary Treatment of Emf Data;103
9.1.8;4.1.8 The Total Cell Emf in Cells with Complex Formation;104
9.1.8.1;4.1.8.1 The Total Emf of Cell B with an Amalgam Indicator Electrode;104
9.1.8.2;4.1.8.2 The Total Emf of Cell H with a H + -Sensitive Indicator Electrode;105
9.1.9;4.1.9 The Validity of the Equations;105
9.2;4.2 Emf Cells Where [A + ] = C M, Is Kept Constant [ 23 ];107
9.2.1;4.2.1 Potential Functions for the Formation of Strong Complexes;108
9.2.1.1;4.2.1.1 The Study of the Formation of Metal Ion Complexes;108
9.2.1.2;4.2.1.2 Survey of the Potential Functions for the Protolysis of the Weak Acid HL;116
9.2.1.3;4.2.1.3 Experimental Studies;121
9.2.1.4;4.2.1.4 Survey of the Potential Functions for the Calculation of the Second Protolysis Constant of the Weak Acid H 2 L;130
9.2.2;4.2.2 Emf Studies on Weak Complex Formation at [A + ] = C M, Constant;133
9.3;4.3 Emf Cells Where [Y ] = C M, Constant [ 35 ];135
9.3.1;4.3.1 Emf Studies Where Strong Complexes Are Formed;136
9.3.1.1;4.3.1.1 Studies on the Formation of Metal Ion Complexes According to Section 4.2.1.1;136
9.3.1.2;4.3.1.2 Survey of the Potential Functions for the Protolysis of the Weak Acid HL, According to Section 4.2.1.2;138
9.3.1.3;4.3.1.3 Experimental Studies;141
9.3.1.4;4.3.1.4 Survey of the Potential Functions for the Protolysis of the Weak Acid H 2 L;145
9.3.2;4.3.2 Emf Studies on Weak Complex Formation at [Y -- ] = C M, Constant;148
9.3.2.1;4.3.2.1 Critical Analysis of the So-Called Self-Medium Method for Cell H;148
9.3.3;4.3.3 Experimental Examples Taken from the Literature;152
9.3.3.1;4.3.3.1 The Hydrolysis of the Lanthanum Ion, La 3+ ;152
9.3.3.2;4.3.3.2 Carbonate Complex Formation of the La 3+ Ion [ 37 ];157
9.4;4.4 Emf Cells Where I = C M, Is Kept Constant [ 38 ];160
9.4.1;4.4.1 Introduction;160
9.4.1.1;4.4.1.1 The Determination of the Constant E 0B ;161
9.4.1.2;4.4.1.2 The Determination of the Constant E 0H ;162
9.4.2;4.4.2 Emf Studies Where Strong Complexes Are Formed At I = C M, Constant;164
9.4.2.1;4.4.2.1 The Main Titration;164
9.4.2.2;4.4.2.2 Studies on the Formation of Metal Ion Complexes;165
9.4.2.3;4.4.2.3 The Calculation of the Total Potential Anomalies in Emf Cells Where Protolysis of the Weak Acids HL and H 2 L Takes Place, Respectively;169
9.4.3;4.4.3 Emf Studies on Weak Complex Formation At I = C M, Kept Constant;173
9.4.4;4.4.4 On the Ionic Medium Dependence of the Equilibrium Constants;175
9.4.4.1;4.4.4.1 Comparison of the Values of the Mentioned Potential Functions Q(H, V) at Different Experimental Conditions;176
9.4.4.2;4.4.4.2 The Dependence of the Equilibrium Constants (log 10 0 pqr ) on the Ionic Medium;178
9.5;4.5 Conclusion on Cells with Complex Formation;181
9.5.1;4.5.1 Strong Complexes Are Formed;181
9.5.2;4.5.2 Weak Complexes Are Formed;184
9.6;4.6 Appendix 1;185
9.7;4.6 Notation Appendix 2;186
9.7.1;4.5.2 Survey of the Estimated Q(H, V) Functions with V = h, b, l = [L 0 ], l = [L 20 ], 0 c A and/or 0 c Y at [A + ] = C M, Is Kept Constant;186
9.7.2;4.5.2 At [Y -- ] = C M, Is Kept Constant;188
9.7.3;4.5.2 At I = C M, Is Kept Constant;188
10;to 5 Estimation of the Total Potential Anomalies and the Determination of the Equilibrium Constants in Emf Cells Where Every Kind of Complex Can Be Present;192
11;to 6 On Emf Titrations Proposed for the Determination of Some Interaction Coefficients;197
11.1;6.1 Introduction;197
11.2;6.2 Survey of Some Emf Cells for Determination of Interaction Coefficients;198
11.2.1;6.2.1 Determination of the Interaction Coefficient (B,Y);198
11.2.2;6.2.2 Determination of 0 (A + = Na, L);199
11.2.3;6.2.3 Determination of 0 0 (B, ClO 4 );202
11.2.4;6.2.4 Determination of (H, L);203
11.2.5;6.2.5 Determination of (A, Cl);205
11.2.6;6.2.6 Determination of 0 0 (A, ClO 4 );206
11.2.7;6.2.7 Determination of (H, Y);207
11.2.8;6.2.8 Determination of (H, Cl);208
11.3;6.3 The Dependence of the Interaction Coefficients on the Ionic Strength;208
11.4;6.4 Experimental;210
11.5;6.5 Appendix 1;211
12;to 7 Emf Titrations Proposed for the Determination of Certain Transport Numbers [1];214
12.1;7.1 Introduction;214
12.2;7.2 Survey of Emf Cells for the Determination of Transport Numbers;215
12.2.1;7.2.1 Determination of Transport Numbers in Strong Electrolyte A e H u L or A y L with Anionic Charges y = e + u =1, 2 or 3;215
12.2.2;7.2.2 The Determination of the Transport Numbers in the Strong Electrolyte BY z(B) Containing An Amalgam-Forming Cation;218
12.2.2.1;7.2.2.1 Cell 7;219
12.2.2.2;7.2.2.2 Cell 8;221
12.2.3;7.2.3 The Determination of the Transport Numbers in Metal Perchlorate Solutions;222
12.2.3.1;7.2.3.1 Cell 9;222
12.2.3.2;7.2.3.2 Cell 10;224
13;to 8 Studies on Emf Cells Where Strong Complexes Are Formed Using Liquid Junctions of the Type AY AY + BYz(B) + HY + AyL At [Y--]INTtie;= C M, Constant, and -- log10 [H+] 7;227
13.1;8.1 Introduction;227
13.2;8.2 The Presentation of the Potential Functions;228
13.2.1;8.2.1 The Calculation of the Ideal Diffusion Potential Term, E D ;229
13.2.2;8.2.2 The Calculation of the Activity Factor Contribution to the Ideal Diffusion Potential, E Df ;230
13.2.3;8.2.3 The Total Emf of Cell B in Alkaline Solutions, with a B z(B)+ Ion-Selective Indicator Electrode and for Small Values of w/a;231
13.2.4;8.2.4 The Total Emf of cell H, in Alkaline Solutions, with a H + Ion-Sensitive Indicator Electrode and for Small Values of w/a;233
13.2.5;8.2.5 Emf Titration Suggested for the Determination of the Experimental Slope Function SL(H, l) and log 10 K 1 Value of the Weak Acid HL;235
13.2.6;8.2.6 The Protolysis of H 2 L in Alkaline Solutions;239
13.3;8.3 Appendix 1 (Chapter 8) The Hydrogen Electrode [13];240
13.3.1;8.2.6 The Preparation of the Hydrogen Electrode by Electrolysis;240
13.3.2;8.2.6 The Thermal Preparation of the Hydrogen Electrode [ 14 ];242
13.3.3;8.2.6 The Total Emf of Cell H with a Hydrogen Indicator Electrode;242
13.4;8.3 Presentation of a New Calibration Method for the Glass Electrode Against the Hydrogen Electrode in Alkaline Solutions;244
14;Index;248