化学学报 ›› 2010, Vol. 68 ›› Issue (03): 227-232. 上一篇    下一篇

研究论文

2-噻吩乙酸的低温热容和热力学性质

高宗华1,史全2,谭志诚*,2,兰孝征3   

  1. (1滨州医学院化学教研室 烟台 264003)
    (2中国科学院大连化学物理研究所 热化学实验室和中国离子液体实验室 大连 116023)
    (3山东农业大学化学与材料科学学院 泰安 271018)
  • 投稿日期:2009-02-12 修回日期:2009-06-20 发布日期:2010-02-20
  • 通讯作者: 谭志诚 E-mail:tzc@dicp.ac.cn
  • 基金资助:

    NSFC No 20373072;20753002

Low-temperature Heat Capacity and Thermodynamic Properties of 2-Thiopheneacetic Acid

Gao Zonghua1 Shi Quan2 Tan Zhicheng*,2 Lan Xiaozheng3   

  1. (1 Department of Chemistry, Binzhou Medical College, Yantai 264003)
    (2 Thermochemistry Laboratory and China Ionic Liquid Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023)
    (3 College of Chemistry and Materials Science, Shandong Agricultural University, Tai'an 271018)
  • Received:2009-02-12 Revised:2009-06-20 Published:2010-02-20

用精密自动绝热量热计测定了2-噻吩乙酸在78~343 K温区内的摩尔热容. 实验结果表明, 在78~314和337~343 K温区内, 该化合物无相变及其他热异常现象发生, 将实验数据拟合得到了该化合物热容随温度变化的多项式方程; 在314~337 K温区内, 该物质发生固-液熔化相变, 其熔化温度、熔化焓、熔化熵及样品纯度分别确定为: 335.745 K, 16.260 kJ•mol-1, 48.415 J•K-1•mol-1和98.555%. 根据热力学函数关系式, 由热容数据计算出了2-噻吩乙酸在80~340 K温区内相对于标准参考温度298.15 K的热力学函数值.

关键词: 2-噻吩乙酸, 绝热量热, 热容, 热力学函数

The low-temperature heat capacity of 2-thiopheneacetic acid was measured in the temperature range from 78 to 343 K with a high precision automated adiabatic calorimeter. No phase transition or other thermal anomaly was observed in the temperature ranges of 78~314 and 337~343 K, in which the molar heat capacities were fitted to two polynomials by means of the least square fitting. A solid-liquid phase transition was observed in the temperature range of 314~337 K. The melting point, molar enthalpy and entropy of fusion, and molar purity of this compound were determined to be 335.745 K, 16.260 kJ•mol-1, 48.415 J•K-1•mol-1 and 98.56%, respectively. The thermodynamic functions of 2-thiopheneacetic acid relative to the reference temperature 298.15 K were derived based on the heat capacity data in the temperature range of 80~340 K.

Key words: 2-thiopheneacetic acid, adiabatic calorimetry, heat capacity, thermodynamic function

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