液体饱和蒸气压测定实验中温度区间的探索

Exploration on Temperature Range for Measuring the Saturated Vapor Pressure of Liquids

大学物理化学实验课程中普遍开设液体饱和蒸气压测定的实验。在该实验中,温度区间是非常重要的实验参数,选择合适的温度区间有利于获得更准确的饱和蒸气压和摩尔汽化热数据。本文以学生实验中普遍采用的纯液体(水)为例,在较宽的温度区间范围内采用静态升温法测定其饱和蒸气压,计算出相应的摩尔汽化热,并对数据误差和误差来源进行了分析讨论,初步得出了水的饱和蒸气压测定实验的最佳温度区间(20~60℃)。

The measurement experiment of saturated vapor pressure for liquids is widely offered from the Physical Chemistry experiment course in universities.Temperature range is a very important experiment parameter in the measurement of saturated vapor pressure for liquids.Choosing suitable temperature range is beneficial for obtaining accurate values for saturated vapor pressure and mole vaporization heat.Herein,taking the widely adopted pure liquid(water)as an example,the saturated vapor pressure was measured using static temperature-raising method within a wide temperature range,and the corresponding mole vaporization heat was calculated.Furthermore,the data error and error source were analyzed and discussed,and thus the optimal temperature range for the measurement of saturated vapor pressure for water was determined to be 20 to 60℃.