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化学学报
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化学学报 ›› 2007, Vol. 65 ›› Issue (14): 1299-1304. 上一篇    下一篇

研究论文

配合物Zn(Met)SO4•H2O(s)的低温热容和标准摩尔生成焓

邸友莹*,1, 高胜利2, 谭志诚3,孙立贤3   

  1. (1聊城大学化学化工学院 聊城 252059)
    (2西北大学化学系 西安 710069)
    (3中国科学院大连化学物理研究所热化学实验室 大连 116023)
  • 投稿日期:2006-11-29 修回日期:2007-01-20 发布日期:2007-07-28
  • 通讯作者: 邸友莹

Low-Temperature Heat Capacities and Standard Molar Enthalpy of Formation of Complex Zn(Met)SO4•H2O(s)

DI You-Ying*,1; GAO Sheng-Li2; TAN Zhi-Cheng3; SUN Li-Xian3   

  1. (1 College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059)
    (2 Department of Chemistry, Northwest University, Xi'an 710069)
    (3 Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023)
  • Received:2006-11-29 Revised:2007-01-20 Published:2007-07-28
  • Contact: DI You-Ying

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利用精密自动绝热热量计直接测定了配合物Zn(Met)SO4•H2O(s) 在78～370 K温区的摩尔热容. 通过热容曲线的解析得到该配合物的起始脱水温度为T0＝329.50 K. 将该温区的摩尔热容实验值用最小二乘法拟合得到摩尔热容 (Cp,m)对温度(T)的多项式方程, 并且在此基础上计算出了它的舒平热容值和各种热力学函数值. 依据Hess定律, 通过设计热化学循环, 选择体积为100 cm3、浓度为2 mol•L－1的盐酸作为量热溶剂, 利用等温环境溶解-反应热量计, 测定和推算出该配合物的标准摩尔生成焓为ΔfHm0＝－(2069.30±0.74) kJ•mol－1.

关键词: Zn(Met)SO4•, H2O(s), 绝热量热法, 低温热容, 溶解-反应量热法, 标准摩尔生成焓

Low-temperature heat capacities of complex Zn(Met)SO4•H2O(s) have been precisely measured with a small sample precision automated adiabatic calorimeter over the temperature range from 78 to 370 K. The initial dehydration temperature of the complex (T0＝329.50 K) has been obtained by means of the analysis of a heat capacity curve. The experimental values of molar heat capacities have been fitted to a polynomial equation of heat capacities (Cp,m) vs. the temperature (T) with the least square method. The smoothed heat capacities and the thermodynamic functions of the complex have been calculated on the basis of the equation. In accordance with Hess law, the standard molar enthalpy of formation for the complex was determined as ΔfHm0＝－(2069.30±0.74) kJ•mol－1, by using an isoperibol solution-reaction calorimeter, designing a thermochemical cycle and choosing 100 mL of 2 mol•dm－3 HCl as calorimetric solvent.

Key words: Zn(Met)SO4•, H2O(s), adiabatic calorimetry, low-temperature heat capacity, isoperibol solution-reaction calorimetry, standard molar enthalpy of formation