2-噻吩乙酸的低温热容和热力学性质  

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

作　　者：高宗华[1] 史全[2] 谭志诚[2] 兰孝征[3] 

机构地区：[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

出　　处：《化学学报》2010年第3期227-232,共6页Acta Chimica Sinica

基　　金：国家自然科学基金(Nos20373072;20753002)资助项目

摘　　要：用精密自动绝热量热计测定了2-噻吩乙酸在78～343K温区内的摩尔热容.实验结果表明,在78～314和337～343K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314～337K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:335.745K,16.260kJ·mol-1,48.415J·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80～340K温区内相对于标准参考温度298.15K的热力学函数值.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.

关 键 词：2-噻吩乙酸 绝热量热 热容 热力学函数 

分 类 号：O626.12[理学—有机化学] O623.11[理学—化学]