基于蒸气压下降法测定物质摩尔质量的实验研究  

Experimental Design of Determination of Molar Mass by Saturated Vapor Pressure Drop Method

作　　者：罗骏 曹茂启 代多芳 王吕清 孟思彤 LUO Jun;CAO Mao-qi;DAI Duo-fang;WANG Lv-qing;MENG Si-tong(School of Chemistry and Chemical Engineering,Qiannan Normal University for Nationalities,Guizhou Duyun 558000,China)

机构地区：[1]黔南民族师范学院化学化工学院,贵州都匀558000

出　　处：《广州化工》2023年第11期108-111,共4页GuangZhou Chemical Industry

基　　金：贵州省科技计划项目(黔科合基础[2019]1297号)。

摘　　要：摩尔质量是物质的一个重要基本参数。物理化学实验中常用凝固点降低法测定物质的摩尔质量,但在实验过程中其凝固点不易判断。本文利用稀溶液饱和蒸气压下降的原理,设计了测定物质摩尔质量的方法和装置,实验原理清晰、操作简单。我们分别对尿素、蔗糖的水溶液和萘的环已烷溶液进行了实验测定,实验测得的尿素、蔗糖和萘的摩尔质量分别为58.1,352.7和121.5 g/mol,与理论值的相对误差分别为3.33%、3.03%和4.50%。饱和蒸气压下降法为测量物质的摩尔质量提供了一种简单的候选方法。Molar mass is an important basic parameter of matter.The freezing point reduction method is commonly used in physical and chemical experiments to determine the molar mass of substances,but its freezing point is difficult to judge in the experimental process.A method and apparatus for the determination of molar mass of dilute solution were designed based on the principle of saturated vapor pressure drop.The molar masses of urea,sucrose and naphthalene were 60.1,342.3 and 127.1 g/mol,respectively.Compared with the theoretical values,the relative errors were only 3.33%,3.03%and 4.05%.The saturated vapor pressure drop method provided a simple candidate method for measuring the molar mass of substances.

关 键 词：饱和蒸气压 凝固点降低 摩尔质量 稀溶液依数性 

分 类 号：O6-339[理学—化学]