电导法测定弱电解质电离常数实验的影响因素探讨

Discussion on the Influence Factors of Ionization Constant Test of Weak Electrolyte by Conductivity Method

电导法测定弱电解质的电离平衡常数实验是一个重要的物理化学实验,电离平衡常数受多种因素的影响。本文探讨了温度和电解质浓度两种主要因素对醋酸弱电解质电离度和电离常数测定的影响。实验在三种不同温度条件下,分别测量了醋酸在不同浓度下的电导率。并采用数据处理方法得出了醋酸在不同温度下的电离常数K_(c)。结果表明,不同温度下,醋酸电离平衡常数的实验值与其理论值相差不大,数量级一致,非常接近(实验相关系数均大于0.99)。浓度一定时,醋酸的电离度随温度升高而增大。而温度一定时,醋酸的电离度随浓度增加而减小;且醋酸的电离平衡常数与温度呈正比线性关系。

The experiment of measuring the ionization equilibrium constant of weak electrolyte by conductivity method is an important physical and chemical experiment,and the ionization equilibrium constant is affected by many factors.In this paper,the effects of temperature and electrolyte concentration on the determination of ionization degree and ionization constant of weak electrolyte in acetic acid were discussed.The conductivity of acetic acid at different concentrations was measured at three different temperatures.The ionization constant K_(c) of acetic acid at different temperatures was obtained by data processing method.The results show that at different temperatures,the experimental values of the ionization equilibrium constant of acetic acid are not significantly different from the theoretical values,and the orders of magnitude are consistent and very close(the experimental correlation coefficients are all greater than 0.99).At a certain concentration,the ionization degree of acetic acid increases with temperature.When the temperature is constant,the ionization degree of acetic acid decreases with the increase of concentration;the ionization equilibrium constant of acetic acid was proportional to temperature.