Thermal Decomposition of Solids and Melts (eBook)

Professor and Head of the Analytical Chemistry department at St. Petersburg State University, Russia.

Preface.-Abbreviations.-Introduction.-Part I. Thermal Decomposition: Primary Concepts: Mechanism: Congruent Dissociative Vaporization.- Direct Observation of Primary Products of Decomposition by Mass Spectrometric Methods.- Induction, Acceleration and Process Localization.- Nucleus Shape and Position.-Peculiarities of Structure and Composition of Solid Product.-Thermal Stability of Complex Gaseous Molecules.- Kinetics: The Arrhenius Equation.- The Hertz–Langmuir Equation and Langmuir Diffusion Equations.- Modification of the Hertz–Langmuir Equation as Applied to Decomposition Reactions.- Equilibrium Pressure of Products in the Equimolar and Isobaric Modes.- Equations for Calculation of the Absolute Rates of Decomposition.- Interpretation of the Arrhenius Parameters by the Use of the Langmuir Evaporation Equations.- Methodology: The Arrhenius-plots Method.- The Second-law Method.-The Third-law Method.- Approximate Evaluation of the Molar Enthalpies.- Reproducibility of Measurements.- Accuracy.- Measurement Time.- Part II. Interpretation and Quantitative Analysis of the Effects, Phenomena and Regularities Accompanying the Decomposition: Decomposition Conditions and the Molar Enthalpy: Ratio of Initial Decomposition Temperature to the Molar Enthalpy.- Thermal Desorption and Criteria for its Identification.- Impact of the Decomposition Mode and Reaction Stoichiometry on the Molar Enthalpy.- Decomposition of Carbonates in the Presence of CO2.- Decomposition of Crystalline Hydrates in the Presence of H2O.- The Self-cooling Effect: The Model of Temperature Calculation.- The Temperature Distribution in Powder Reactants.- Corrections to the Kinetic Parameters.- Experimental Evaluation of Self-cooling.- The Topley–Smith Effect: Experimental Observations.- Modeling of the Topley–Smith Effect for Li2SO4 .H2O.- Modeling of the Topley–Smith Effect for CaCO3.- Impact of Vapour Condensation on the Enthalpy Change: The Contribution of the Condensation Energy to the Enthalpy Change.- Increase of the Enthalpy Change with Temperature.- Reactant Melting and the Decomposition Enthalpy.- Thermochemical Analysis of the Composition of the Primary Decomposition Products.- Effect of the Crystalline Structure of a Substance on the Composition of the Primary Decomposition Products: Oxides.- Nitrides.- Phosphorous, Arsenic and Antimony.- Evaporation Coefficients.- The Kinetic Compensation Effect.- Conclusions.- Part III. Thermal Decomposition of Individual Substances: Instruments for Thermogravimetric Measurements.- Measurement Conditions and Procedures for Thermogravimetric Studies: Evaluation of the Absolute Rate of Decomposition.- Choice of the Decomposition Temperature.- Choice of the Residual Pressure of Air in the Reactor (equimolar mode).- Decomposition in the Presence of the Gaseous Product (isobaric mode).- Decomposition of Hydrates in Air and Carbonates in Argon and Air.- Evaporation and Decomposition of Some Substances: Non-metals (phosphorus).- Metalloids (arsenic, antimony).- Oxides.- Higher Oxides for IV Group of Metals.- Sulfides, Selenides and Tellurides.- Nitrides.- Azides.- Hydroxides.- Clays.- Hydrates.- Nitrates.- Sulfates.- Carbonates.- Oxalates.- Final conclusions.- Appendices: Fundamental Physical Constants.- Atomic Masses of Elements.- Coefficients of Mutual Diffusion of Gases.- Spectral and Integrated Emittance of Some Metals and Oxides.- Composition of Dry Atmospheric Air.- Saturation Pressure of Water Vapour.- Subject Index.