Abstract: The molar heat capacity values of the binary system composed of 0.716 molar fraction H₂O+0.284 molar fraction n-C₄H₉OH were measured by an adiabatic calorimeter in the temperature range from 78 K to 320 K.The functional relationships of heat capacity with respect to thermodynamic temperature were established.Glass-transition occurred at(111.9±1.2)K.The phase transitions took place at (179.26±0.77)K and (269.69±0.14)K corresponding to the solid-liquid phase transitions of n-butanol and water, respectively. The phase-transition enthalpy and entropy of water were calculated. The thermodynamic functions of the binary systems 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 temperature.

摘要： 用全自动低温绝热量热计测定了水和正丁醇二元体系（0.716 H₂O+0.284 n-C₄H₉OH）在78～320 K温区的摩尔热容C_p，m.建立了C_p，m与温度T的函数关系.结果表明，该水和正丁醇二元混合体系在（111.9±1.2）K发生玻璃化转变，在（179.26±0.77）K和（269.69±0.14）K发生分别对应正丁醇和水的固液相变.获得了水的相变焓和相变熵.计算了以298.15 K为基准的混合物的热力学函数.