The standard electromotive forces of the reversible cells consisted of the Corning monovalent general cation selective electrode (M + ISE) and chloride selective electrode (Cl ISE), namely Cl --ISE｜RbCl( m ),H 2O(1- x ),DMF( x )｜M +-ISE have been measured, and the standard free energies of transfer(Δ S t ) of RbCl from H 2O to mixtures of H 2O DMF have been calculated, the standard transfer entropies(Δ S t ) have been also calculated from temperature coefficients of Δ G t of RbCl at seven temperatures from 283.15 K to 318.15 K. The behavior of change of Δ S t of RbCl with experimental temperature and mole fraction ( x ) of DMF in the mixed solvents and its influence on the structure of the mixed solvents were discussed on the basis of solvation theory ofelectrolyte solution.
本文测定了298.15 K 下氯化钠、氯化钾在水和水与四种丁醇异构体混合溶剂中的双电池电动势,从电动势值计算了转移自由能,并测定了288.15,308.15,318.15 K下氯化钠、氯化钾在水和水与叔丁醇混合溶剂中的双电池电动势.采用的双电池为:Ag|AgCl|MCl(s)|M(Hg)|MCl(w)|AgCl|Ag(w 为水,s 为含水混合溶剂,M 为 Na、K).采用 Abraham 的离子溶剂化一层连续介质模型,计算了氯化钠、氯化钾在这四种混合溶剂中的溶剂化自由能,其中静电部分采用 Abraham 所给公式计算,非静电部分采用 Pierotti 定标粒子理论计算.在低的醇含量时,转移自由能的计算结果与实验基本符合.此外,根据含叔丁醇体系电动势的温度系数计算得转移熵,对该体系的结构作了定性讨论.
