Author(s)

Yoshihiro Kudo^*, Shoichi Katsuta

Graduate School of Science, Chiba University, Chiba, Japan.

An idea on interfacial equilibrium-potential differences () which are generated for the extraction of univalent metal picrate (MPic) and divalent ones (MPic₂) by crown ethers (L) into high-polar diluents was improved. These potentials were clarified with some experimental extraction-data reported before on the M = Ag(I), Ca(II), Sr(II) and Ba(II) extraction with 18-crown-6 ether (18C6) and benzo-18C6 into 1,2-dichloroethane (DCE) and nitrobenzene (NB). Consequently, it was demonstrated that the  values from the extraction-experimentally obtained logK_D,Pic ones are in agreement with or close to those calculated from charge balance equations in many cases, where the symbol, K_D,Pic, denotes an individual distribution constant of Pic^﹣ into the DCE or NB phase. Also, it was experimentally shown that extraction constants based on the overall extraction equilibria do not virtually contain the  terms in their functional expressions.

Extraction Constants, Distribution Constant of a Single Ion, Interfacial Equilibrium-Potential Differences, 1, 2-Dichloroethane, Nitrobenzene, Metal Picrates, Crown Ethers

Kudo, Y. and Katsuta, S. (2015) On an Expression of Extraction Constants without the Interfacial Equilibrium-Potential Differences for the Extraction of Univalent and Divalent Metal Picrates by Crown Ethers into 1,2-Dichloroethane and Nitrobenzene. American Journal of Analytical Chemistry, 6, 350-363. doi: 10.4236/ajac.2015.64034.