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�.