An Introduction to Aqueous Electrolyte Solutions

An Introduction to Aqueous Electrolyte Solutions is a comprehensive coverage of the subject including the development of key concepts and theory that focus on the physical rather than the mathematical aspects. Important links are made between the study of electrolyte solutions and other branches of chemistry, biology, and biochemistry, making it a useful cross-reference tool for students studying this important area of electrochemistry.

Carefully developed throughout, each chapter includes intended learning outcomes and worked problems and examples to encourage student understanding of this multidisciplinary subject.

• a comprehensive introduction to aqueous electrolyte solutions including the development of key concepts and theories

• emphasises the connection between observable macroscopic experimental properties and interpretations made at the molecular level

• key developments in concepts and theory explained in a descriptive manner to encourage student understanding

• includes worked problems and examples throughout

An invaluable text for students taking courses in chemistry and chemical engineering, this book will also be useful for biology, biochemistry and biophysics students required to study electrochemistry.

Auteur
Margaret Robson Wright is the author of An Introduction to Aqueous Electrolyte Solutions, published by Wiley.

Contenu

Preface xix

Preliminary Chapter Guidance to Student xxiii

List of symbols xxv

1 Concepts and Ideas: Setting the Stage 1

1.1 Electrolyte solutions what are they? 2

1.2 Ions simple charged particles or not? 4

1.3 The solvent: structureless or not? 7

1.4 The medium: its structure and the effect of ions on this structure 8

1.5 How can these ideas help in understanding what might happen when an ion is put into a solvent? 9

1.6 Electrostriction 11

1.7 Ideal and non-ideal solutions what are they? 11

1.8 The ideal electrolyte solution 14

1.9 The non-ideal electrolyte solution 14

1.10 Macroscopic manifestation of non-ideality 15

1.11 Species present in solution 17

1.12 Formation of ion pairs from free ions 17

1.13 Complexes from free ions 21

1.14 Complexes from ions and uncharged ligands 21

1.15 Chelates from free ions 22

1.16 Micelle formation from free ions 22

1.17 Measuring the equilibrium constant: general considerations 23

1.18 Base-lines for theoretical predictions about the behaviour expected for a solution consisting of free ions only, Debye-Hu¨ckel and Fuoss-Onsager theories and the use of Beer's Law 24

1.19 Ultrasonics 26

1.20 Possibility that specific experimental methods could distinguish between the various types of associated species 29

1.21 Some examples of how chemists could go about inferring the nature of the species present 29

2 The Concept of Chemical Equilibrium: An Introduction 33

2.1 Irreversible and reversible reactions 34

2.2 Composition of equilibrium mixtures, and the approach to equilibrium 34

2.3 Meaning of the term 'position of equilibrium' and formulation of the equilibrium constant 35

2.4 Equilibrium and the direction of reaction 39

2.5 A searching problem 44

2.6 The position of equilibrium 45

2.7 Other generalisations about equilibrium 46

2.8 K and pK 46

2.9 Qualitative experimental observations on the effect of temperature on the equilibrium constant, K 47

2.10 Qualitative experimental observations on the effect of pressure on the equilibrium constant, K 49

2.11 Stoichiometric relations 49

2.12 A further relation essential to the description of electrolyte solutions electrical neutrality 50

3 Acids and Bases: A First Approach 53

3.1 A qualitative description of acidbase equilibria 54

3.2 The self ionisation of water 56

3.3 Strong and weak acids and bases 56

3.4 A more detailed description of acidbase behaviour 57

3.5 Ampholytes 60

3.6 Other situations where acid/base behaviour appears 62

3.7 Formulation of equilibrium constants in acidbase equilibria 66

3.8 Magnitudes of equilibrium constants 67

3.9 The self ionisation of water 67

3.10 Relations between Ka and Kb: expressions for an acid and its conjugate base and for a base and its conjugate acid 68

3.11 Stoichiometric arguments in equilibria calculations 70

3.12 Procedure for calculations on equilibria 71

4 Equilibrium Calculations for Acids and Bases 73

4.1 Calculations on equilibria: weak acids 74

4.2 Some worked examples 80

4.3 Calculations on equilibria: weak bases 85

4.4 Some illustrative problems 90

4.5 Fraction ionised and fraction not ionised for a weak acid; fraction protonated and fraction not protonated for a weak base 97

4.6 Dependence of the fraction ionised on pKa and pH 98

4.7. The effect of dilution on the fraction ionised for weak acids lying roughly in the range: pKa ¼ 4.0 to 10.0 101

4.8 Reassessment of the two approximations: a rigorous expression for a weak acid 103

4.9 Conjugate acids of weak bases 104

4.10 Weak bases 105

4.11 Effect of non-ideality 105

5 Equilibrium Calculations for Salts and Buffers 107

5.1 Aqueous solutions of salts 108 5.2 Salts of strong acids/strong bases 108&...