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


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
  • 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).


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)