Two extraction constants (Kex± and Kex) for extraction of silver picrate (Ag﹢Pic﹣) by benzo-15-crown-5 ether (B15C5) and benzo-18-crown-6 one (B18C6) into 1,2-dichloroethane (DCE) and dichloromethane (DCM) were...Two extraction constants (Kex± and Kex) for extraction of silver picrate (Ag﹢Pic﹣) by benzo-15-crown-5 ether (B15C5) and benzo-18-crown-6 one (B18C6) into 1,2-dichloroethane (DCE) and dichloromethane (DCM) were determined at 298 K and given values of ionic strength. Here, Kex± and Kex were expressed as [AgL﹢]o[Pic﹣]o/[Ag﹢][L]o[Pic﹣] and [AgLPic]o/[Ag﹢][L]o[Pic﹣], respectively: L symbolizes B15C5 or B18C6 and the subscript “o” denotes the organic phase composed of DCE or DCM. Individual distribution constants (KD,Pic) of picrate ion, Pic﹣, into the two diluents were also determined with the determination of Kex. From comparison of these KD,Pic values with those standardized, interfacial potential differences () at extraction equilibria were evaluated. Then, using these values, relations of the experimentally-determined logKex± or logKex values with their electrochemically-standardized ones were precisely discussed. Consequently, it was indicated that logKex± should be expressed as a function of .展开更多
文摘Two extraction constants (Kex± and Kex) for extraction of silver picrate (Ag﹢Pic﹣) by benzo-15-crown-5 ether (B15C5) and benzo-18-crown-6 one (B18C6) into 1,2-dichloroethane (DCE) and dichloromethane (DCM) were determined at 298 K and given values of ionic strength. Here, Kex± and Kex were expressed as [AgL﹢]o[Pic﹣]o/[Ag﹢][L]o[Pic﹣] and [AgLPic]o/[Ag﹢][L]o[Pic﹣], respectively: L symbolizes B15C5 or B18C6 and the subscript “o” denotes the organic phase composed of DCE or DCM. Individual distribution constants (KD,Pic) of picrate ion, Pic﹣, into the two diluents were also determined with the determination of Kex. From comparison of these KD,Pic values with those standardized, interfacial potential differences () at extraction equilibria were evaluated. Then, using these values, relations of the experimentally-determined logKex± or logKex values with their electrochemically-standardized ones were precisely discussed. Consequently, it was indicated that logKex± should be expressed as a function of .
