摘要
实验假设水溶液中电解质浓度非常低时,AgNO_3水溶液中银离子的活度α(Ag^+)与KCl水溶液中氯离子的活度α(Cl^-)相等。依此假设条件设计原电池,使该原电池的电池反应为AgCl→Ag^++Cl^-,后采用补偿法测量一定温度下原电池中AgNO_3溶液浓度和KCl溶液浓度发生变化时的电池电动势E。依据能斯特方程和Debye-Huckel极限公式,推导出原电池电动势与电解质的平均活度系数及溶液浓度的关系,用外推法作图得到此电池反应的标准电动势E~θ。由平衡常数与原电池标准电动势的关系,得到氯化银的溶度积Ksp(AgCl)。
Take the assumption that in aqueous,the activity of silver ion and chloride ion both at very low concentration were equal,the primary cell was designed according to this assumption,while its cell reaction is Ag Cl→ Ag~＋＋Cl^-. And then,we take the compensation method to get the electromotive force of the primary cell while the concentrations of AgNO_3 and KCl in aqueous changes. Relationship between electromotive force and the mean activity coefficients of electrolytes and the solution concentration was deduced according to the Nernst equation and the limit Debye-Huckel formula. Standard electromotive force Eθwas obtained by extrapolation mapping,finally,the solubility product of silver chloride was calculated through the relationship between equilibrium constant and electromotive force of primary cells.
出处
《实验室科学》
2016年第3期34-37,共4页
Laboratory Science
关键词
活度系数法
原电池
溶度积常数
activity coefficient method
primary cell
solubility product
