Behaviour of the silver-silver bromide and the silver-silver iodide electrodes in formamide at different temperatures

Abstract

From the e.m.f. measurements of the buffered cells of the type                       Pt, H₂|HOAc(m₁), KOAc(m₂), KX(m₃)|AgX-Ag the standard potentials of the Ag-AgX electrodes have been determined, in formamide, at nine different temperatures in the range 5-45°. The standard potentials of the Ag-AgX electrodes obtained at 25° are in good agreement with those obtained from the study of the cells                    Ag-AgX|KX(m₃), KOAc(m₂), HOAc(m₁), QH₂-Q|Pt at 25°, where X is Br or I. The cell                          Pt,H₂|HBr(m)|AgBr-Ag has been further studied in this solvent at 25° with a view to having an independent check on these buffered cells for the standard potential of the Ag-AgBr electrode. The standard thermodynamic quantities (ΔG°, ΔH°, and ΔS°) for the corresponding cell reactions have been calculated from the e.m.f. data over the range, 5-45°.