Standard electrode potentials in molten chlorides

Abstract

The apparent standard electrode potential for the system Pt(II)/Pt(0) in molten MgCl 2-NaCl-KCl (50:30:20 mole per cent) as solvent at 475°C was measured. On the mole-fraction scale this is —0·0760 ± 0·0008 V vs the standard chlorine reference. Based on this, the apparent standard electrode potentials of other systems, earlier reported vs Pt(II)/Pt(0), are converted to standard chlorine as reference. For four typical systems, Ag(I)/Ag(0), Pb(II)/Pb(0), Ni(II)/Ni(0) and Co(II)/Co(0), apparent standard electrode potentials vs standard chlorine reference were also measured; these agreed with the converted values to within 2–10 mV. Electrode potentials in this solvent are also compared with those reported in molten LiCl-KCl and in molten NaCl-KCl as solvent.