The electromotive forces (emF) E-A and E-C of the following concentration cells with transference: Ag/AgCl/KCl(m(2))parallel to KCl (m(1))\AgCl\Ag and KxHg1-x\KCl (m(1))parallel to KCl (m(2))\KxHg1-x, respectively, together with the emfs E-MAX of the corresponding double cell without transference: KxHg1-xKCl (m(1))\AgCl\Ag-Ag\AgCl\KCl (m(2))\KxHg1-x have been measured at KCl molalities m (m(1) fixed and m(2) varied, with m(2) > m(1)) approximately up to the KCl solubility limit in 12 solvent mixtures for the three aqueous-oganic solvent systems (ethylene glycol + water),(acetonitrile + water), and (1,4-dioxane + water) up to 0.8 mass fraction of organic component. For all the cases explored, the E-A vs. E-MAX relation is linear over the whole KCI molality range. The ionic transference numbers tof KCI determined therefrom show a curvilinear dependence on the mass fraction of the organic component of the relevant solvent mixture and are found to fall in the range 0.52-0.48, viz, within +/-4% of exact equitransference (t(+) = t(-) = 0.5). In particular, KCI becomes exactly equitransferent (i.e., an ideal salt bridge) in aqueous mixtures with the following mass fractions of organic component: 0.4 ethylene glycol and 0.09 acetonitrile, as well as 0.12 methanol, and 0.08 and 0.34 ethanol from our recent work. Even if use of KCI as a salt bridge would be somewhat restricted by its limited solubility in high mass fractions of dioxane and acetonitrile and pending extension of investigation to other mixed-solvent systems, the above figures characterize KCI as a fairly good "intersolvental" salt bridge in electrochemistry, electroanalysis, and corrosion science.
Characterization of potassium chloride as an equitransferent "intersolvental" salt bridge / A. Manzoni, P.R. Mussini, T. Mussini. - In: JOURNAL OF SOLUTION CHEMISTRY. - ISSN 0095-9782. - 28:12(1999 Dec), pp. 1329-1340.
|Titolo:||Characterization of potassium chloride as an equitransferent "intersolvental" salt bridge|
MUSSINI, PATRIZIA ROMANA (Secondo)
MUSSINI, TORQUATO (Ultimo)
|Parole Chiave:||Mixed solvents; Salt bridges; Transference cells; Transference numbers|
|Settore Scientifico Disciplinare:||Settore CHIM/01 - Chimica Analitica|
Settore CHIM/02 - Chimica Fisica
|Data di pubblicazione:||dic-1999|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1023/A:1021748008137|
|Appare nelle tipologie:||01 - Articolo su periodico|