.5 - To Replace The Thermodynamic Properties Of The Base Isophthalic Acid Sodium Salt

Material basic thermodynamic data can be used to predict the direction of chemical reactions and optimize the reaction conditions. Basic thermodynamic data, such as Entropy, Enthalpy, Gibbs free energy, are important class of basic data in the process of physical and chemical changes of matter. In this dissertation, Sodium isophthalic acid and sodium derivatives of isophthalic acid were selected as research target. The basic thermodynamic data of was measured and calculated, through Adiabatic calorimetry, microcalorimetry and combustion calorimetry. The contents and conclusion were described as follows:(1) A series of sodium isophthalic acid derivatives 5-R-Na2bdc·nH2O (H2bdc= isophthalic acid, R=H, NH2, OH, CH3, NO2, n=0.5,1,1,1,1) were synthesized in deionized water and samples'purity were characterized. Through combustion calorimetry and microcalorimetry, the standard molar enthalpy of solution and constant volume energy were measured. Others basic thermodynamic data of as-prepared samples were determined from the standard molar enthalpy of solution and other auxiliary thermodynamic data, such as standard molar enthalpy of formation, standard enthalpy of the hydrated anion through a thermochemical cycle.(2) Molar enthalpies of dissolution (ΦL) of the samples in double-distilled water under various molalities were determined at 298.15 K by an RD496- 2000 type microcalorimeter. Following Pitzer's theory, the molar enthalpy of dissolution of the as-prepared samples at infinite dilution (ΔsolHm∞), Pitzer's parameters(βMX(0)L,βMX(1)L) and relative partial molar enthalpies(L1, L2) were obtained. In order to seek the law to support structural basis, system compare with calculated results and explore the thermodynamic data and the regularity of Pitzer model parameters.(3) Low-temperature mole heat capacities of the as-prepared samples were determined from 78K～400K. Under the corresponding statistical mathematics methods calculate he thermodynamic functions of the measurement temperature region.