物理化学学报 >> 2013, Vol. 29 >> Issue (10): 2129-2134.doi: 10.3866/PKU.WHXB201309101

热分析动力学和热动力学 上一篇    下一篇

配位化合物Zn(Met)3(NO3)2·H2O(s)(Met=L-α-蛋氨酸)的低温热容及标准摩尔生成焓

张国春, 周春生, 高胜利   

  1. 商洛学院化学化工系, 陕西 商洛 726000
  • 收稿日期:2013-06-12 修回日期:2013-09-09 发布日期:2013-09-26
  • 通讯作者: 高胜利 E-mail:gaoshli@nwu.edu.cn
  • 基金资助:

    国家自然科学基金(21273171 21127004, 21173168)和陕西省教育厅专项基金(11JK0578, 11JS110)资助项目

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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摘要：

利用精密绝热热量仪测定了化合物配合物Zn(Met)3(NO3)2·H2O (s) (Met=L-α-蛋氨酸)在78-371 K温区的摩尔热容. 通过热容曲线解析, 得到了该配合物的起始脱水温度为TD=325.10 K. 将该温区的摩尔热容实验值用最小二乘法拟合得到了摩尔热容(Cp)对约化温度(T)的多项式方程, 由此计算得到了配合物的舒平热容值和热力学函数值. 基于设计的热化学循环, 选择100 mL of 2 mol·L-1 HCl为量热溶剂, 利用等温环境溶解-反应热量计, 得到了298.15 K配合物的标准摩尔生成焓为ΔfHm0[Zn(Met)3(NO3)2·H2O(s),s]=-(1472.65±0.76) J·mol-1.

关键词: 绝热量热法, 热容, 标准摩尔生成焓, 溶解-反应量热法, Zn(Met)3(NO3)2·H2O(s)

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)