Acid-base equilibria of water in melts, table of equilibrium constant values, 314 Acidity of metal aquo complexes, 132 Acidobasicity of water in molten salts, 311 Acids in dilute solution, pk values, 130 Activities of components of Dead Sea water, 99, 100 AgCl/ Ag 2S mixtures-collected thermodynamic data, 380 Alkali metal oxides in melts, thermodynamic data, 199 Aluminum halide-alkali metal halide molten salt systems acid-base chemistry, 408 electrochemistry of elemental and dissociated chalcogens, 410 species characterization, 409 stability of organic radical ions, 411 Anion basicity, 128 Anionic hydration, 11 scattering length and sample parameters, 12 Aqueous cesium chloride, computer simulation, 49, 50 Aqueous glasses CaZnC14 solutions, 22, 23 nitrate-bound water, 25 Basicity moderating parameter, -y, 129 Behavior of chalcogenides in chloroaluminates, 366 Binary molten salt mixture, schematic representation, 15 3 Cation-bound water in hydrate melts, relaxation rates, 16 Cation-bound water in the glassy state, reason for dielectric activity, 22 Cationic hydration, 8 parameters obtained from neutron diffraction, 10 scattering length and sample parameters, 9 Charge-transfer-to-solvent electrochemical and spectral correlations, 92 Charge-transfer-to-solvent spectra comparison of models fore max prediction, 83 concept, 80 Coulombic interaction components, 89 and Coulombic interactions, 85 effect of electrolytes, 84 expanded lattice models (of electrolyte solutions), 86 interionic distances, 88 maximum absorption energies, other models, 83 "polaron" model, 81 quantitative treatment, 81 Smith-Symons "confined" model, 82 Stein-Treinin "diffuse" model, 82 temperature dependence of E max, linearity, 91 variation with concentration, 86 445
446 Charge-transfer-to-solvent spectral shifts activity coefficient correlation, 90 thermodynamic correlations, 94 Chloride ion hydration, 13 Classification of molten salts, 151 Comparison of calculated and experimental molalities: sodium chloride in equilibrium with halite and potassium chloride in equilibrium with carnallite, 107 Comparison of polysulfides in melts effect of basicity, 402 electrochemistry, 403 stability, 403 Comparison of Tl, Ag, Pb, Cu results (halide-chalcogenide melts), 376, 379 Competitive polarization in melts, 426, 427,431 Complex ions in melts, 5 Computer simulation: interfaces, 51 Computer simulation techniques molecular dynamics, polarization, 36,40 Monte Carlo method, 29 review, 28 Concentration ranges for water+ salt mixtures, 148 Condition of electroneu trality, applied to aqueous solutions and melts, 156 Conductance Arrhenius plots, 6 2 data, concentrated solutions, 72 Conductivities temperature dependence, 298 and activation energies, 298 and relation to maxima, 299 water concentration dependence of, 295 and comparison of hydrated to crystallographic radii, 29 8 and position of maxima, 296 relation to hydration numbers, 297 relation to hydration numbers and cation composition, 298 Contribution of polarization to ml'<ing in mixtures of LiF-LiCl-NaF-NaCl, 429 Cooperative effects in tranport processes, 150 Copper and iron sulfide/chloride systems, 375 Dead Sea, 97 composition, 98 water compared with ocean water, 99 Debye-Hi.ickel theory ex tensions, 58 Monte Carlo tests, 32 Deleterious effects of w:1ter on extractive processes, 325 Determination of solubility of water in molten salts, 306, 7 Dielectric activity: rotational source, 24 Differing behavior of water in LiCl-KCl and NaCl-KCl, 313 DiffusioP. coefficients: data, concentrated solutions, 7 4 Distribution of electrons in metal-molten salt solutions, 442 Dynamic properties of ionic liquids, 40 Effects of water in molten salts: predictions, 331 Electric transport in binary molten salt mixtures and in aqueous solutions of binary electrolytes, 154 Electrochemistry of water in molten salts, 169 acetates, 178 autocatalytic model, 175 chlorides, 17 6 effect on double layer capacities, 175 hydroxides, 177 influence upon anodic processes, 17 2 influence on electrode processes, 178 nitrates and nitrites, 170 solvated electron model, 174 Electrodes for measuring oxide ion concentrations, 312 Electrolysis of PbS in chloride melts, 366 Electrolytes in a multicomponent electrolyte solution, equations for calculations of osmotic and activity coefficients, 101, 102, 103 Electron donor power, 129 Electrostriction in molten salts and highly concentrated electrolyte solutions, 1 Enthalpy of mixing, electrostatic energy term, 430 Enthalpy of solution of Na in NaCl, 441 Equilibrium constants for anionic oxygen reactions in NaN03-KN03, 204 Fluctuating polarization, 440
447 Free energy of mixing MgClrCaC12, 436 Friction coefficients for molten salts and aqueous solutions, 159 Friction coefficients for the system LiN03 + AgN03 at 260 C (table), 161 Friction coefficients for the system LiN03 + AgN03 at 260 C as a function of the mole fraction of silver nitrate, 162 Germanium sulfide/germanium iodide melts, 368 Hammett acidity function, Ho, 136 aqueous solu!ions of ZnC12, 136 Heats of mixing: MgCl2 + Ca02; MgCl2 + SrCl2, 434, 435 Hydrated melts, relaxation studies, 15 Hydration shells: ions in Dead Sea water and end brine, 109 Hydrogen density distribution contours, simulation, 48 Hydrogen in molten salts acetates, 250 bisulfates, 252 anodic hydrogen dissolution, 254 cathodic hydrogen evolution, 253 carbonates, 255 role of carbon monoxide, 255 chlorides, 25 7 electrode reactions, 25 7 chloroaluminates, 259 electrochemistry, 260 diffusion coefficients, 252!1uorides, 261 electrochemistry, 261 hydroxides, 26 2 acid-base behavior, 262 electrochemistry, 263 nitrates, 264 activation energy, 269 electrochemical studies, 2 71 C02, H20/C03 2 -,H 2 system, 278 H20/H2,0H- system, 275 mechanisms, 276 pot en tiometry, 2 72 potentiometry, catalysis, 2 73 voltammetry, 273 ESCA studies, 280 Henry's law applicability, 266 Hydrogen in molten salts (cont.) kinetics, 26 7 manometric studies, 265 pressure-time relationship, 268, 270 solubility products, 267 other melts, 264 solubility and thermodynamic data, 251 Hydrolysis of chlorides, 312 of!1uorides, 315, 317 of hydroxides, 317 of nitrates, 318 Hydroxide melts, 301 conductivities, 302 comparisons with other melts, 302 and transport mechanisms, 302 inl1uence of water, 303 and proton mobility, 303 Interdiffusion in binary molten salt mbltures and in aqueous electrolyte solutions of binary electrolytes, 155 Ion pairs and ion triplet interactions, aqueous solutions, 112 Ionic contact radii in gases and crystals, 2 Ions in water, simulation, 4 7 Isotherms for potassium chloride, Monte Carlo calculations, 33, 34 Lead sulfide-alkali chloride melts, 369 Lead sulfide-lead halide melts, 367 Loss tangent spectra, aqueous glasses, 19, 20 Madelung constants, derivation from spectral shifts, 9 3 Mechanism of transport, relation of phenomenological parameters, 3 00 Melting, 4 Melts, resonance effects, 6 Metal aqua complexes, predicted acidity, 139 Metal-electrolyte interface aqueous: Hg, 118 aqueous: solid metals, 119 C -E data, main characteristics, 120 current model, 121 internal inconsistencies, 121 effect of ion size, 124 experimental methods: C-E determinations, 119
448 Metal-electrolyte interface (cont.) modified diffuse layer theory, 123 molten salts: solid metals, 119 new experiments, 124 simple diffuse layer theory, 122 Methods for describing the structure of molten salts and electrolyte solutions, 14 7 Microwave dielectric measurements, 16 Mobilities anion, 67 cation, 67 interaction, 69 Molar volumes and additivity, 294 and ion hydration, 294 water concentration dependence of, 292 Ca(N03h 4H20 system, 292 LiNOrKN03 system, 293 NH4N03-NH4Cl-LiN03 system, 292 Molecular dynamics, density distribution functions, 45 Molten salt mixtures, behavior of magnesium chloride, 433 Molten salt purification methods chemical, 213, 219 desiccation, 211, 227, 232 filtration, 227, 232, 242 physical methods, 210 principles, 209 recrystallization, 212, 22 7 reduced pressure, 211,227,232 sublimation, 211, 242 zone refining, 213 Molten salt solvents, purification general considerations, 188 purity availabilities, 187 purity requirements, 186 residual impurity levels, 197, 215 technological interests, 188 Molten salt technologies, 165 Nature of chalcogenide species in melts, 365 Neutron first-order difference method, 7 nmr studies, concentrated solutions, 137 Onsager reciprocal relations, validity, 68 Oxide equilibria in chloride melts, 216 Oxide species in miscellaneous melts, 3 56 Oxide species in miscellaneous melts (cont.) carbonates, 358 fluorides, 35 8 multiple oxide equilibria in hydroxide melts, 357 oxygen electrode response in chloride melts, 356 sulfates, 357 Oxide species in molten salts, 339 acid-base equilibrium constants in KN03, 348 an acid-base scale for oxyanions in KN03, 349 cryoscopic methods, 352 manometric methods, 353 solubility determinations, 35 2 spectroscopic methods, 352 thermogravimetry, 352 voltammetric methods, 350 oxide species in nitrates, 350 volumetric analysis, 353 basicity in glasses, 341 and gas solubilities, 342 and leachability of glasses, 341 and slag formation, 341 and sulfur formation, 343 and water solubility, 343 congruent melting and compound formation, 340 optical basicity and p-block ion probes, 345 qualitative estimation, 340 quantitative estimation, 345 potentiometric methods, 345 acid titrations, 34 7 oxygen electrodes, 345 use of acid-base indicators, 344 use of organic indicators, 345 Oxide species in nitrate melts, 3 53 stabilization by silica, 354 Oxoacidity scales, molten chlorides (figure), 316 Oxygen density distribu lion con tours, simulation, 49 Oxygen electrode in melts, 199 Phase diagrams for metal chloride and metal sulfide mixtures, 364 Phenomenological coefficients, On sager relations, 158ff
449 pk-optical basicity relation acids, 131 acid dissociation of hydrated cations, 134 pk values for metal ions in aqueous solutions, 133 Polarization, importance in determining thermodynamic properties of molten salt mixtures, 425 Polyatomic ions in molten salts, inorganic and organic, 3 Pourbaix-type diagram for iron in molten NaCl-KCl, 329 for noble metals in molten NaOH-KOH, 332 for various species in NaCl-KCl-CeCl 3, 330 Precipitation of salts from brines, 106 from Dead Sea brines, 104 Precision, relative, of experimental data, 70 Proton chemical shift vs. Hammett acidity function (HN0 3 and HCl) relation, 138 Proton magnetic shift constant, concentrated solutions, 140 Radial distribution functions, simulated KCl, 38 Redox properties of water, 317 in chlorides, 320, 321 in hydroxides, 3 22 in nitrates, 322 Regular solutions, 430 Relation between excess entropy and enthalpy: MgClrCaCl2 and other systems, 43 7 Relationship between cation-anion distance and polarizability of anion in alkali earth halides, 432 Relaxation data, aqueous glasses, interpretation, 21 Relaxation spectra cooling techniques, 16 experimental data, 18, 19 experimental procedures, 17 Reviews of transport properties of molten salts and electrolytic solutions, 145, 146 Room-temperature chloroaluminate-based melts, 412 Room-temperature ch1oroaluminate-based melts (cont.) acid-base chemistry and pcl values, 415 as a function of composition, 417 potentiometric evidence, 415 n -butylpyridinium chloride mixtures, 413 electrochemistry and spectroscopy of aromatic hydrocarbons, 417 correlation with ionization potentials, 418 correlation with solid state complexes, 418 formation of radical cations, 419 electrochemistry of the Fe(III)/Fe(Il) system, 420 physical properties, 420 species characterization, 413 compositional variations, 414 Raman shifts, 413 use as battery electrolytes, 4 21 Separation of titanium and iron in melts, 326 Silver chloride-silver sulfate melts, electrical conductivities, 3 73 Silver chloride-sulfide melts, enthalpies of mixing, 379 Silver halide-silver chalcogenide systems, 369 densities and molar volumes, 3 71 molar volumes as function of mol% Ag2S, 372 phase studies, 3 74 Simulation, polar systems, 43 Solubility and reactivity of water in molten salts, 188 chlorides and fluorides, 189 nitrates, 203 electrochemical data, 207 oxyanion solvents, 202 temperature dependence of Henry's law constant, 194 Solubility data for water in molten salts (table), 308, 309 Solubility of metal oxides in NaOH-KOH, 327 Solubility ranges of aluminum species in LiCl-KCl, 326 Solutions of sodium in NaCl, 440 Spectral probe ions, 84
450 Standard molar Gibbs free energies of formation and dissolution, 105 Structural aspects in Dead Sea brines, 108 Structure of NaCl: comparison of MD and neutron-scattering experiments, 39 Sulfides in molten lead chloride, 392 importance in lead electrolysis, 392 and anodic reaction, 392 and chronopotentiometric studies, 393 influence on cathodic yield, 392 and other electrochemical methods, 393 initial oxidation step, 394 second oxidation step, 395 subsequent reaction, 396 sulfur dissolution and polysulfide formation, 395 Sulfur compounds in molten NaOH-water mixtures, 396 coulometry, 401 elemental sulfur, 397 polysulfides, 396 spectroscopic characterization, 397 stability, spectra and electrochemistry, 399 the sulfide ion, 396 voltammetry of sulfides, 399 Solubility of water (see also Solubility and reactivity of water) in chlorides, hydroxides, 307 in molten nitrates and nitrites, 206, 307 electrochemical detection, 207, 231 impurity chloride ions detection, 212 impurity nitrite ions, 208 impurity oxide ions, 208 in molten salts, 306 Solubility of water and hydrogen chloride in chloride melts, 190 effect of solute polarity, 192 electrochemical detection, 192, 234, 236 hydrolysis and dissociation, 196 hydroxide formation, 197 oxide formation, 198 nature of solution species, 19 5 Sulfur species in chloroaluminate melts acid-base chemistry, 389 electrochemistry, 3 90 acid melts, 391 basic melts, 3 90 solubility, 389 Sulfur species in LiCl-KCl, 365 electrochemistry, 3 8 8 solubility, 387 Sulfur species in LiCl-KCl (cont.) spectroscopy, 388 Sulfur species in miscellaneous melts, NaCl-KCl, 391 thiocyanates, 391 Sulfur vapor electrode, 374 Thallous sulfide-chloride mixture, 382 activity coefficients, 383 Theories and models of water-salt mixtures for discussion of transport processes, 149 Thermodynamics and structure, 2 7 and transport properties for the system LiN03 + AgN03 at 260 C (table), 157 Tin chalcogenide-tin halide melts, 368 Transference numbers, data, concentrated solutions, 7 3 Transport application of irreversible thermodynamics to, 66 concentration dependence of, 6 3 cooperative nature of, 60 phenomenological coefficients for, 66 quasi-lattice models for, 59 temperature dependence parameters for, 61 theories of, 58 transition state models for, 59 Transport experiments and results, 156ff Transport numbers, relation to ion velocity, 152 Velocity correlation coefficients, 69 Viscosity concentration dependence of, 65 data, concentrated solutions, 71 water concentration dependence of, 299 and comparison with conductivities, 299 Water in molten salts, 165 effect on aluminum electroplating, 168 effect on corrosion and passivation, 166 role in TORCO process, 169 solubility, 166 X-ray and neutron diffraction studies of concentrated solutions, 110