Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (10): 2129-2134.doi: 10.3866/PKU.WHXB201309101

• THERMALANALYSIS KINETICS ANDTHERMOKINETICS • Previous Articles     Next Articles

Low Temperature Heat Capacities and Standard Molar Enthalpy of Formation of the Coordination Compound Zn(Met)3(NO3)2·H2O(s)(Met=L-α-Methionine)

ZHANG Guo-Chun, ZHOU Chun-Sheng, GAO Sheng-Li   

  1. Department of Chemistry & Chemical Engineering, Shangluo University, Shangzhou 726000, Shaanxi Province, P. R. China
  • Received:2013-06-12 Revised:2013-09-09 Published:2013-09-26
  • Contact: GAO Sheng-Li E-mail:gaoshli@nwu.edu.cn
  • Supported by:

    The project was support by the National Natural Science Foundation of China (21273171 21127004, 21173168) and Scientific Research Program Funded by Shaanxi Provincial Education Department, China (11JK0578, 11JS110).

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Abstract:

Low temperature heat capacities of the compound Zn(Met)3(NO3)2·H2O(s) have been measured by a precision automated adiabatic calorimeter over the temperature range 78-371 K. The initial dehydration temperature of the coordination compound was determined to be TD=325.10 K by analysis of the heat-capacity curve. The experimental values of the molar heat capacities in the temperature region have been fitted to a polynomial equation of heat capacities with the reduced temperature (X), [X=f(T)], by the least squares method. Smoothed heat capacities and thermodynamic functions relative to the standard reference temperature 298.15 K of the compound are derived from the fitted polynomial equation and listed at 5 K internals. Using 100 mL of 2 mol·L-1 HCl(aq) as calorimetric solvent, with an isoperibol solution-reaction calorimeter, the standard molar enthalpy of formation of the compound was determined to be ΔfHm0[Zn(Met)3(NO3)2×H2O(s), s]=-(1472.65±0.76) J·mol-1 by a designed thermochemical cycle.

Key words: Adiabatic calorimetry, Heat capacity, Standard molar enthalpy of formation, Isoperibol solution-reaction calorimetry, Zn(Met)3(NO3)2·H2O (s)