The transference no. [t] of lithium sulfate in acetonitrile/water and methanol/water solvent mixts. was studied by measuring the emf. of transference cells: Pb(Hg)|PbSO4|Li2SO4 (m2)||Li2SO4 (m1)|PbSO4|Pb(Hg), Hg|Hg2SO4|Li2SO4 (m2)||Li2SO4 (m1)|Hg2SO4|Hg, and LixHg1-x|Li2SO4 (m1)||Li2SO4 (m2)|LixHg1-x, to evaluate Li2SO4 as an unsym. salt bridge for minimization of liq. junction potentials in potentiometric applications. In water, Li2SO4 is nearly as good a salt bridge as KCl; this effectiveness was verified in a pH-meter cell using various aq. pHS stds. In acetonitrile/water solvents contg. 0.09 wt. fraction of acetonitrile at 298.15 K, Li2SO4 shows exact ionic equi-transference, obeying the general condition t+/z+ = t-/|z-|. The Li2SO4 salt bridge can be used for simple insertion between electrolyte solns. to minimize the liq. junction potential, as the outer component of a double-bridge arrangement of any ref. electrode, or, in sulfate-reversible ref. electrodes as the supporting and bridge electrolyte. The operation potential of the Hg|Hg2SO4|2 m Li2SO4 ref. electrode in aq. solns. is 0.6326 V at 298.15 K.
Characterization of Lithium Sulfate as an Unsymmetrical-Valence Salt Bridge for the Minimization of Liquid Junction Potentials in Aqueous-Organic Solvent Mixtures / C.L. Faverio, P.R. Mussini, T. Mussini. - In: ANALYTICAL CHEMISTRY. - ISSN 0003-2700. - 70:13(1998 Jul 01), pp. 2589-2595.
|Titolo:||Characterization of Lithium Sulfate as an Unsymmetrical-Valence Salt Bridge for the Minimization of Liquid Junction Potentials in Aqueous-Organic Solvent Mixtures|
MUSSINI, PATRIZIA ROMANA (Secondo)
MUSSINI, TORQUATO (Ultimo)
|Settore Scientifico Disciplinare:||Settore CHIM/01 - Chimica Analitica|
Settore CHIM/02 - Chimica Fisica
|Data di pubblicazione:||1-lug-1998|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1021/ac980014b|
|Appare nelle tipologie:||01 - Articolo su periodico|