Modern Electrochemistry

Volume 1.- 1 Electrochemistry.- 1.1 Introduction.- 1.2 Electrons at and across Interfaces.- 1.2.1 Many Properties of Materials Depend upon Events Occurring at Their Surfaces.- 1.2.2 Almost All Interfaces Are Electrified.- 1.2.3 The Continuous Flow of Electrons across an Interface: Electrochemical Reactions.- 1.2.4 Electrochemical and Chemical Reactions.- 1.3 Basic Electrochemistry.- 1.3.1 Electrochemistry before 1950.- 1.3.2 The Treatment of Interfacial Electron Transfer as a Rate Process: The 1950’s.- 1.3.3 Quantum Electrochemistry: The 1960’s.- 1.3.4 Ions in Solution, as well as Electron Transfer across Interfaces.- 1.4 The Relation of Electrochemistry to Other Sciences.- 1.4.1 Some Diagrammatic Presentations.- 1.4.2 Some Examples of the Involvement of Electrochemistry in Other Sciences.- 1.4.3 Electrochemistry as an Interdisciplinary Field, Apart from Chemistry?.- 1.5 Electrodics and Electronics.- 1.6 Transients.- 1.7 Electrodes are Catalysts.- 1.8 The Electromagnetic Theory of Light and the Examination of Electrode Surfaces.- 1.9 Science, Technology, Electrochemistry, and Time.- 1.9.1 Do Interfacial Charge-Transfer Reactions Have a Wider Significance Than Has Hitherto Been Realized?.- 1.9.2 The Relation between Three Major Advances in Science, and the Place of Electrochemistry in the Developing World.- 2 Ion—Solvent Interactions.- 2.1 Introduction.- 2.2 The Nonstructural Treatment of Ion—Solvent Interactions.- 2.2.1 A Quantitative Measure of Ion—Solvent Interactions.- 2.2.2 The Born Model: A Charged Sphere in a Continuum.- 2.2.3 The Electrostatic Potential at the Surface of a Charged Sphere.- 2.2.4 On the Electrostatics of Charging (or Discharging) Spheres.- 2.2.5 The Born Expression for the Free Energy of Ion—Solvent Interactions.- 2.2.6 The Enthalpy and Entropy of Ion—Solvent Interactions.- 2.2.7 Can One Experimentally Study the Interactions of a Single Ionic Species with the Solvent?.- 2.2.8 The Experimental Evaluation of the Heat of Interaction of a Salt and Solvent.- 2.2.9 How Good Is the Born Theory?.- Further Reading.- 2.3 Structural Treatment of the Ion—Solvent Interactions.- 2.3.1 The Structure of the Most Common Solvent, Water.- 2.3.2 The Structure of Water near an Ion.- 2.3.3 The Ion—Dipole Model of Ion—Solvent Interactions.- 2.3.4 Evaluation of the Terms in the Ion—Dipole Approach to the Heat of Solvation.- 2.3.5 How Good Is the Ion—Dipole Theory of Solvation?.- 2.3.6 The Relative Heats of Solvation of Ions on the Hydrogen Scale.- 2.3.7 Do Oppositely Charged Ions of Equal Radii Have Equal Heats of Solvation?.- 2.3.8 The Water Molecule Can Be Viewed as an Electrical Quadrupole.- 2.3.9 The Ion—Quadrupole Model of Ion—Solvent Interactions.- 2.3.10 Ion—Induced-Dipole Interactions in the Primary Solvation Sheath.- 2.3.11 How Good Is the Ion—Quadrupole Theory of Solvation?.- 2.3.12 The Special Case of Interactions of the Transition-Metal Ions with Water.- 2.3.13 Some Summarizing Remarks on the Energetics of Ion—Solvent Interactions.- Further Reading.- 2.4 The Solvation Number.- 2.4.1 How Many Water Molecules Are Involved in the Solvation of an Ion?.- 2.4.2 Static and Dynamic Pictures of the Ion—Solvent Molecule Interaction.- 2.4.3 The Meaning of Hydration Numbers.- 2.4.4 Why Is the Concept of Solvation Numbers Useful?.- 2.4.5 On the Determination of Solvation Numbers.- Further Reading.- 2.5 The Dielectric Constant of Water and Ionic Solutions.- 2.5.1 An Externally Applied Electric Field Is Opposed by Counterfields Developed within the Medium.- 2.5.2 The Relation between the Dielectric Constant and Internal Counterfields.- 2.5.3 The Average Dipole Moment of a Gas-Phase Dipole Subject to Electrical and Thermal Forces.- 2.5.4 The Debye Equation for the Dielectric Constant of a Gas of Dipoles.- 2.5.5 How the Short-Range Interactions between Dipoles Affect the Average Effective Moment of the Polar Entity Which Responds to an External Field.- 2.5.6 The Local Electric Field in a Condensed Polar Dielectric.- 2.5.7 The Dielectric Constant of Liquids Containing Associated Dipoles.- 2.5.8 The Influence of Ionic Solvation on the Dielectric Constant of Solutions.- Further Reading.- 2.6 Ion—Solvent—Nonelectrolyte Interactions.- 2.6.1 The Problem.- 2.6.2 The Change in Solubility of a Nonelectrolyte Due to Primary Solvation.- 2.6.3 The Change in Solubility Due to Secondary Solvation.- 2.6.4 The Net Effect on Solubility of Influences from Primary and Secondary Solvation.- 2.6.5 The Case of Anomalous Salting in.- Further Reading.- Appendix 2.1 Free Energy Change and Work.- Appendix 2.2 The Interaction between an Ion and a Dipole.- Appendix 2.3 The Interaction between an Ion and a Water Quadrupole.- 3 Ion—Ion Interactions.- 3.1 Introduction.- 3.2 True and Potential Electrolytes.- 3.2.1 Ionic Crystals Are True Electrolytes.- 3.2.2 Potential Electrolytes: Nonionic Substances Which React with the Solvent to Yield Ions.- 3.2.3 An Obsolete Classification: Strong and Weak Electrolytes.- 3.2.4 The Nature of the Electrolyte and the Relevance of Ion—Ion Interactions.- Further Reading.- 3.3 The Debye—Hückel (or Ion-Cloud) Theory of Ion—Ion Interactions.- 3.3.1 A Strategy for a Quantitative Understanding of Ion—Ion Interactions.- 3.3.2 A Prelude to the Ionic-Cloud Theory.- 3.3.3 How the Charge Density near the Central Ion Is Determined by Electrostatics: Poisson’s Equation.- 3.3.4 How the Excess Charge Density near the Central Ion Is Given by a Classical Law for the Distribution of Point Charges in a Coulombic Field.- 3.3.5 A Vital Step in the Debye—Hückel Theory of the Charge Distribution around Ions: Linearization of the Boltzmann Equation.- 3.3.6 The Linearized Poisson—Boltzmann Equation.- 3.3.7 The Solution of the Linearized P—B Equation.- 3.3.8 The Ionic Cloud around a Central Ion.- 3.3.9 How Much Does the Ionic Cloud Contribute to the Electrostatic Potential ?r at a Distance r from the Central Ion?.- 3.3.10 The Ionic Cloud and the Chemical-Potential Change Arising from Ion-Ion Interactions.- Further Reading.- 3.4 Activity Coefficients and Ion-Ion Interactions.- 3.4.1 The Evolution of the Concept of Activity Coefficient.- 3.4.2 The Physical Significance of Activity Coefficients.- 3.4.3 The Activity Coefficient of a Single Ionic Species Cannot Be Measured.- 3.4.4 The Mean Ionic Activity Coefficient.- 3.4.5 The Conversion of Theoretical Activity-Coefficient Expressions into a Testable Form.- Further Reading.- 3.5 The Triumphs and Limitations of the Debye—Hückel Theory of Activity Coefficients.- 3.5.1 How Well Does the Debye—Hückel Theoretical Expression for Activity Coefficients Predict Experimental Values?.- 3.5.2 Ions Are of Finite Size, Not Point Charges.- 3.5.3 The Theoretical Mean Ionic-Activity Coefficient in the Case of Ionic Clouds with Finite-Sized Ions.- 3.5.4 The Ion-Size Parameter a.- 3.5.5 Comparison of the Finite-Ion-Size Model with Experiment.- 3.5.6 The Debye—Hückel Theory of Ionic Solutions: An Assessment.- 3.5.7 On the Parentage of the Theory of Ion-Ion Interactions.- Further Reading.- 3.6 Ion—Solvent Interactions and the Activity Coefficient.- 3.6.1 The Effect of Water Bound to Ions on the Theory of Deviations from Ideality.- 3.6.2 Quantitative Theory of the Activity of an Electrolyte as a Function of the Hydration Number.- 3.6.3 The Water-Removal Theory of Activity Coefficients and Its Apparent Consistency with Experiment at High Electrolytic Concentrations.- Further Reading.- 3.7 The So-Called “Rigorous” Solutions of the Poisson—Boltzmann Equation.- Further Reading.- 3.8 Temporary Ion Association in an Electrolytic Solution: Formation of Pairs, Triplets, etc.- 3.8.1 Positive and Negative Ions Can Stick Together: Ion-Pair Formation.- 3.8.2 The Probability of Finding Oppositely Charged Ions near Each Other.- 3.8.3 The Fraction of Ion Pairs, According to Bjerrum.- 3.8.4 The Ion-Association Constant KA of Bjerrum.- 3.8.5 Activity Coefficients, Bjerrum’s Ion Pairs, and Debye’s Free Ions.- 3.8.6 The Fuoss Approach to Ion-Pair Formation.- 3.8.7 From Ion Pairs to Triple Ions to Clusters of Ions.- Further Reading.- 3.9 The Quasi-Lattice Approach to Concentrated Electrolytic Solutions.- 3.9.1 At What Concentration Does the Ionic-Cloud Model Break Down?.- 3.9.2 The Case for a Cube-Root Law for the Dependence of the Activity Coefficient on Electrolyte Concentration.- 3.9.3 The Beginnings of a Quasi-Lattice Theory for Concentrated Electrolytic Solutions.- Further Reading.- 3.10 The Study of the Constitution of Electrolytic Solutions.- 3.10.1 The Temporary and Permanent Association of Ions.- 3.10.2 Electromagnetic Radiation, a Tool for the Study of Electrolytic Solutions.- 3.10.3 Visible and Ultraviolet Absorption Spectroscopy.- 3.10.4 Raman Spectroscopy.- 3.10.5 Infrared Spectroscopy.- 3.10.6 Nuclear Magnetic Resonance Spectroscopy.- Further Reading.- 3.11 A Perspective View on the Theory of Ion—Ion Interactions.- Appendix 3.1 Poisson’s Equation for Spherically Symmetrical Charge Distribution.- Appendix 3.2 Evaluation of the Integral $$\int_{r = 0}^{r \to \infty } {{e^{ - (\chi r)}}} (\chi r)d(\chi r)$$.- Appendix 3.3 Derivation of the Result $${f_ + } = {(f_ + ^{{\nu _ + }} + f_ - ^{{\nu _ - }})^{1/\nu }}$$.- Appendix 3.4 To Show That the Minimum in the Pr versus r Curve Occurs at r = ?/2.- Appendix 3.5 Transformation from the Variable r to the Variable y = ?/r.- Appendix 3.6 Relation Between Calculated and Observed Activity Coefficients.- 4 Ion Transport in Solutions.- 4.1 Introduction.- 4.2 Ionic Drift under a Chemical-Potential Gradient: Diffusion.- 4.2.1 The Driving Force for Diffusion.- 4.2.2 The “Deduction” of an Empirical Law: Fick’s First Law of Steady-State Diffusion.- 4.2.3 On the Diffusion Coefficient D.- 4.2.4 Ionic Movements: A Case of the Random Walk.- 4.2.5 The Mean Square Distance Traveled in a Time t by a Random-Walking Particle.- 4.2.6 Random-Walking Ions and Diffusion: The Einstein—Smoluchowski Equation.- 4.2.7 The Gross View of Non-Steady-State Diffusion.- 4.2.8 An Often Used Device for Solving Electrochemical Diffusion Problems: The Laplace Transformation.- 4.2.9 Laplace Transformation Converts the Partial Differential Equation Which Is Fick’s Second Law into a Total Differential Equation.- 4.2.10 The Initial and Boundary Conditions for the Diffusion Process Stimulated by a Constant Current (or Flux).- 4.2.11 The Concentration Response to a Constant Flux Switched on at t = 0.- 4.2.12 How the Solution of the Constant-Flux Diffusion Problem Leads On to the Solution of Other Problems.- 4.2.13 Diffusion Resulting from an Instantaneous Current Pulse.- 4.2.14 What Fraction of Ions Travels the Mean Square Distance ?x2? in the Einstein—Smoluchowski Equation?.- 4.2.15 How Can the Diffusion Coefficient Be Related to Molecular Quantities?.- 4.2.16 The Mean Jump Distance l, a Structural Question.- 4.2.17 The Jump Frequency, a Rate-Process Question.- 4.2.18 The Rate-Process Expression for the Diffusion Coefficient.- 4.2.19 Diffusion: An Overall View.- Further Reading.- 4.3 Ionic Drift under an Electric Field: Conduction.- 4.3.1 The Creation of an Electric Field in an Electrolyte.- 4.3.2 How Do Ions Respond to the Electric Field?.- 4.3.3 The Tendency for a Conflict between Electroneutrality and Conduction.- 4.3.4 The Resolution of the Electroneutrality-versus-Conduction Dilemma: Electron-Transfer Reactions.- 4.3.5 The Quantitative Link between Electron Flow in the Electrodes and Ion Flow in the Electrolyte: Faraday’s Law.- 4.3.6 The Proportionality Constant Relating the Electric Field and the Current Density: The Specific Conductivity.- 4.3.7 Molar Conductivity and Equivalent Conductivity.- 4.3.8 The Equivalent Conductivity Varies with Concentration.- 4.3.9 How the Equivalent Conductivity Changes with Concentration: Kohlrausch’s Law.- 4.3.10 The Vectorial Character of Current: Kohlrausch’s Law of the Independent Migration of Ions.- Further Reading.- 4.4 The Simple Atomistic Picture of Ionic Migration.- 4.4.1 Ionic Movements under the Influence of an Applied Electric Field.- 4.4.2 What Is the Average Value of the Drift Velocity?.- 4.4.3 The Mobility of Ions.- 4.4.4 The Current Density Associated with the Directed Movement of Ions in Solution, in Terms of the Ionic Drift Velocities.- 4.4.5 The Specific and Equivalent Conductivities in Terms of the Ionic Mobilities.- 4.4.6 The Einstein Relation between the Absolute Mobility and the Diffusion Coefficient.- 4.4.7 What Is the Drag (or Viscous) Force Acting on an Ion in Solution?.- 4.4.8 The Stokes—Einstein Relation.- 4.4.9 The Nernst—Einstein Equation.- 4.4.10 Some Limitations of the Nernst—Einstein Relation.- 4.4.11 A Very Approximate Relation between Equivalent Conductivity and Viscosity: Walden’s Rule.- 4.4.12 The Rate-Process Approach to Ionic Migration.- 4.4.13 The Rate-Process Expression for Equivalent Conductivity.- 4.4.14 The Total Driving Force for Ionic Transport: The Gradient of the Electrochemical Potential.- Further Reading.- 4.5 The Interdependence of Ionic Drifts.- 4.5.1 The Drift of One Ionic Species May Influence the Drift of Another.- 4.5.2 A Consequence of the Unequal Mobilities of Cations and Anions, the Transport Numbers.- 4.5.3 The Significance of a Transport Number of Zero.- 4.5.4 The Diffusion Potential, Another Consequence of the Unequal Mobilities of Ions.- 4.5.5 Electroneutrality Coupling between the Drifts of Different Ionic Species.- 4.5.6 How Does One Represent the Interaction between Ionic Fluxes? The Onsager Phenomenological Equations.- 4.5.7 An Expression for the Diffusion Potential.- 4.5.8 The Integration of the Differential Equation for Diffusion Potentials: The Planck—Henderson Equation.- Further Reading.- 4.6 The Influence of Ionic Atmospheres on Ionic Migration.- 4.6.1 The Concentration Dependence of the Mobility of Ions.- 4.6.2 Ionic Clouds Attempt to Catch Up with Moving Ions.- 4.6.3 An Egg-Shaped Ionic Cloud and the “Portable” Field on the Central Ion.- 4.6.4 A Second Braking Effect of the Ionic Cloud on the Central Ion: The Electrophoretic Effect.- 4.6.5 The Net Drift Velocity of an Ion Interacting with Its Atmosphere.- 4.6.6 The Electrophoretic Component of the Drift Velocity.- 4.6.7 The Procedure for Calculating the Relaxation Component of the Drift Velocity.- 4.6.8 How Long Does an Ion Atmosphere Take to Decay?.- 4.6.9 The Quantitative Measure of the Asymmetry of the Ionic Cloud Around a Moving Ion.- 4.6.10 The Magnitude of the Relaxation Force and the Relaxation Component of the Drift Velocity.- 4.6.11 The Net Drift Velocity and Mobility of an Ion Subject to Ion—Ion Interactions.- 4.6.12 The Debye—Hückel—Onsager Equation.- 4.6.13 The Theoretical Predictions of the Debye—Hückel—Onsager Equation versus the Observed Conductance Curves.- 4.6.14 A Theoretical Basis for Some Modifications of the Debye—Hückel—Onsager Equation.- Further Reading.- 4.7 Nonaqueous Solutions: A New Frontier in Ionics?.- 4.7.1 Water Is the Most Plentiful Solvent.- 4.7.2 Water Is Often Not an Ideal Solvent.- 4.7.3 The Debye—Hückel—Onsager Theory for Nonaqueous Solutions.- 4.7.4 The Solvent Effect on the Mobility at Infinite Dilution.- 4.7.5 The Slope of the ? versus c½ Curve as a Function of the Solvent.- 4.7.6 The Effect of the Solvent on the Concentration of Free Ions: Ion Association.- 4.7.7 The Effect of Ion Association upon Conductivity.- 4.7.8 Even Triple Ions Can Be Formed in Nonaqueous Solutions.- 4.7.9 Some Conclusions about the Conductance of Nonaqueous Solutions of True Electrolytes.- Further Reading.- Appendix 4.1 The Mean Square Distance Traveled by a Random-Walking Particle.- Appendix 4.2 The Laplace Transform of a Constant.- Appendix 4.3 A Few Elementary Ideas on the Theory of Rate Processes.- Appendix 4.4 The Derivation of Equations (4.257) and (4.258).- Appendix 4.5 The Derivation of Equation (4.318).- 5 Protons in Solution.- 5.1 The Case of the Nonconforming Ion: The Proton.- 5.2 Proton Solvation.- 5.2.1 What Is the Condition of the Proton in Solution?.- 5.2.2 Proton Affinity.- 5.2.3 The Overall Heat of Hydration of a Proton.- 5.2.4 The Coordination Number of a Proton.- Further Reading.- 5.3 Proton Transport.- 5.3.1 The Abnormal Mobility of a Proton.- 5.3.2 Protons Conduct by a Chain Mechanism.- 5.3.3 Classical Proton Jumps and Proton Mobility.- 5.3.4 Do Proton Jumps Obey Classical Laws?.- 5.3.5 Quantum-Mechanical Proton Jumps and Proton Mobility.- 5.3.6 Water Reorientation, a Prerequisite for Proton Jumps.- 5.3.7 The Rate of Water Reorientation and Proton Mobility.- 5.3.8 A Picture of Proton Mobility in Aqueous Solutions.- 5.3.9 The Rate-Determining Water-Rotation Model of Proton Mobility and the Other Anomalous Facts.- 5.3.10 Proton Mobility in Ice.- 5.3.11 The Existence of the Hydronium Ion from the Point of View of Proton Mobility.- 5.3.12 Why Is the Mechanism of Proton Mobility So Important?.- Further Reading.- 5.4 Homogeneous Proton-Transfer Reactions and Potential Electrolytes.- 5.4.1 Acids Produce Hydrogen Ions and Bases Produce Hydroxyl Ions: The Initial View.- 5.4.2 Acids Are Proton Donors, and Bases Are Proton Acceptors: The Brönsted View.- 5.4.3 The Dissolution of Potential Electrolytes and Other Types of Proton-Transfer Reactions.- 5.4.4 An Important Consequence of the Brönsted View: Conjugate Acid-Base Pairs.- 5.4.5 The Absolute Strength of an Acid or a Base.- 5.4.6 The Relative Strengths of Acids and Bases.- 5.4.7 Proton Free-Energy Levels.- 5.4.8 The Primary Effect of the Solvent upon the Relative Strength of an Acid.- 5.4.9 A Secondary (Electrostatic) Effect of the Solvent on the Relative Strength of Acids.- Further Reading.- 6 Ionic Liquids.- 6.1 Introduction.- 6.1.1 The Limiting Case of Zero Solvent: Pure Liquid Electrolytes.- 6.1.2 The Thermal Dismantling of an Ionic Lattice.- 6.1.3 Some Features of Ionic Liquids (Pure Liquid Electrolytes).- 6.1.4 Liquid Electrolytes Are Ionic Liquids.- 6.1.5 The Fundamental Problems in Pure Liquid Electrolytes.- Further Reading.- 6.2 Models of Simple Ionic Liquids.- 6.2.1 The Origin of Liquid Electrolyte Models.- 6.2.2 Lattice-Oriented Models.- 6.2.2a The Experimental Basis for Model Building.- 6.2.2b The Need to Pour Empty Space into a Fused Salt.- 6.2.2c The Vacancy Model: A Fused Salt Is an Ionic Lattice with Numerous Vacancies.- 6.2.2d The Hole Model: A Fused Salt Is Full of Holes like Swiss Cheese.- 6.2.3 Gas-Oriented Models for Liquid Electrolytes.- 6.2.3a The Cell-Theory Approach.- 6.2.3b The Free Volume Belongs to the Liquid and Not to the Particles: The Liquid Free-Volume Model.- 6.2.4 A Summary of the Models for Liquid Electrolytes.- Further Reading.- 6.3 Quantification of the Hole Model for Liquid Electrolytes.- 6.3.1 An Expression for the Probability That a Hole Has a Radius between r and r + dr.- 6.3.2 The Fürth Approach to the Work of Hole Formation.- 6.3.3 The Distribution Function for the Size of the Holes in a Liquid Electrolyte.- 6.3.4 What Is the Average Size of a Hole?.- Further Reading.- 6.4 Transport Phenomena in Liquid Electrolytes.- 6.4.1 Some Simplifying Features of Transport in Fused Salts.- 6.4.2 Diffusion in Fused Salts.- 6.4.2a Self-Diffusion in Pure Liquid Electrolytes: It May Be Revealed by Introducing Isotopes.- 6.4.2b Results of Self-Diffusion Experiments.- 6.4.3 The Viscosity of Molten Salts.- 6.4.4 What Is the Validity of the Stokes—Einstein Relation in Ionic Liquids?.- 6.4.5 The Conductivity of Pure Liquid Electrolytes.- 6.4.6 The Nernst—Einstein Relation in Ionic Liquids.- 6.4.6a The Nernst—Einstein Relation: Its Degree of Applicability.- 6.4.6b The Gross View of Deviations from the Nernst—Einstein Equation.- 6.4.6c Possible Molecular Mechanisms for Nernst—Einstein Deviations.- 6.4.7 Transport Numbers in Pure Liquid Electrolytes.- 6.4.7a Some Ideas about Transport Numbers in Fused Salts.- 6.4.7b The Measurement of Transport Numbers in Liquid Electrolytes.- 6.4.7c A Radiotracer Method of Calculating Transport Numbers in Molten Salts.- 6.4.7d A Stokes’ Law Approach to a Rough Estimate of Transport Numbers.- Further Reading.- 6.5 The Atomistic View of Transport Processes in Simple Ionic Liquids.- 6.5.1 Holes and Transport Processes.- 6.5.2 What Is the Mean Lifetime of Holes in Fused Salts?.- 6.5.3 Expression for Viscosity in Terms of Holes.- 6.5.4 The Diffusion Coefficient from the Hole Model.- 6.5.5 A Critical Test of a Model for Ionic Liquids Is a Rationalization of the Heat of Activation of 3.7RTm for Transport Processes.- 6.5.6 An Attempt to Rationalize ED = E? = 3.7 RTm.- 6.5.7 The Hole Model, the Most Consistent Present Model for Liquid Electrolytes.- Further Reading.- 6.6 Mixture of Simple Ionic Liquids—Complex Formation.- 6.6.1 Mixtures of Simple Ionic Liquids May Not Behave Ideally.- 6.6.2 Interactions Lead to Nonideal Behavior.- 6.6.3 Can One Meaningfully Refer to Complex Ions in Fused Salts?.- 6.6.4 Raman Spectra, and Other Means of Detecting Complex Ions.- Further Reading.- 6.7 Mixtures of Liquid Oxide Electrolytes.- 6.7.1 The Liquid Oxides.- 6.7.2 Pure Fused Nonmetallic Oxides Form Network Structures Like Liquid Water.- 6.7.3 Why Does Fused Silica Have a Much Higher Viscosity Than Do Liquid Water and the Fused Salts?.- 6.7.4 The Solvent Properties of Fused Nonmetallic Oxides.- 6.7.5 Ionic Additions to the Liquid-Silica Network: Glasses.- 6.7.6 The Extent of Structure Breaking of Three-Dimensional Network Lattices and Its Dependence on the Concentration of Metal Ions.- 6.7.7 The Molecular and Network Models of Liquid Silicate Structure.- 6.7.8 Liquid Silicates Contain Large Discrete Polyanions.- 6.7.9 The “Tceberg” Model.- 6.7.10 Fused-Oxide Systems in Metallurgy: Slags.- Further Reading.- Appendix 6.1 The Effective Mass of a Hole.- Appendix 6.2 Some Properties of the Gamma Function.- Appendix 6.3 The Kinetic Theory Expression for the Viscosity of a Fluid.