水-乙醇二元体系共沸混合物的热力学研究  

Thermodynamic Investigation of the Azeotrope of Water and Ethanol

作　　者：南照东[1] 谭志诚[2] 孙立贤[2] 

机构地区：[1]曲阜师范大学化学系,曲阜273165 [2]中国科学院大连化学物理研究所热化学实验室,大连116023

出　　处：《物理化学学报》2004年第6期626-630,共5页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(20073047)资助项目~~

摘　　要：用全自动低温绝热量热计测定了水、乙醇以及水和乙醇组成的共沸混合物在不同温区的摩尔热容Cρ.m建立了共沸混合物Cρ,m与温度T的函数关系,结果表明,水和乙醇组成的共沸混合物在98.496 K发生玻璃态转化,在158.939 K和270.95 K发生固-液相变.获得了其相应的相变焓和相变熵.计算了以298.15 K为基准的该共沸混合物的热力学函数和超额热力学函数.The molar heat capacities of the azeotrope in the binary system of water and ethanol were measured by an adiabatic calorimeter in the temperature range from 78 K to 320 K. The functions of the heat capacity with respect to the thermodynamic temperature were established. The glass transition occurred at 98. 496 K. The phase transitions took place in the temperature ranges from 123.08 K to 156.96 K and 269.03 K to 273.20 K corresponding to the solid-solid phase transition of ethanol, solid-liquid phase transition of ethanol, and solid-liquid phase transition of water, respectively. The thermodynamic functions and the excess thermodynamic functions of the azeotrope relative to 298.15 K were derived based on the relationships of the thermodynamic functions and the function of the measured heat capacity with respect to the temperature.

关 键 词：绝热量热法 热容 共沸混合物 水 乙醇 

分 类 号：O642.3[理学—物理化学]