Abstract:
With twice-distilled water as the solvent, 2-pyrazinyl acid dihydrate zinc (Zn (pyza) 2 (H2O) 2 (s)) was synthesized, and its crystal structure was characterized bny X-ray diffraction method.By using TG / DSC technique, the behavior for the thermal decomposition of the compound were revealed. Using automatic adiabatic calorimeter, the complex at 80 ～ 400 K of the low-temperature heat capacity was measured.Based on the results,and the least squares fitting, the formula of complex the molar heat capacity versus the equivalent temperature was obtained, and the smoothed heat capacities of the compound and various thermodynamic function data were calculated. Based on thermochemical cycle principle, the use of dissolution-reaction calorimeter under isothermal environment, the designed heat chemical reaction enthalpy of the reactants and products dissolved in the selected were measured, solvents and the reaction enthalpy is -(49.555±0.403) kJ / mol. Using Hess′s law, the standard molar enthalpy of 2- pyridine triazine zinc carboxylate was -(858.62±2.30) kJ / mol.Using UV-visible spectrometer, the speatra of the reactants and products solution were measured.Based on the spectra results, the reliability of the designed thermochemical cycle is confirmed.
