Standard Potentials of the Silver /Silver Chloride Electrode at Different Temperatures and related Thermodynamic Quantities in Ethanol - Water Media

Physical Chemistry Section, Department of Chemical Technology, University of Calcutta, Calcutta-700 009 Manuscript received 20 March 1989, accepted 9 August 1989 The standard molal potentials (Eom) of the cells of the type, Pt, H2(g,1,atm) I HCl (m) in EtOH —H2O ǀ Agcl, Ag at five temperatures in the range 15-35° have been determined in ethanol -water media. The El values as a function of celsius temperature t in different solvent compositions have been calculated based on the equation, Em= ao + bo(t-25)+ co (t —25) The values of a°, b° and c° have been calculated by least-square method. The related thermodynamic quantities have been calculated. The dependence of standard potentials at 25° on the dielectric constant of the media (in the light of Born equation), the volume fraction Ow) and the mole fraction (Nw,) of water (based on Feakins-French relationship) have been examined. The variation of thermodynamic quantities ∆ G° ∆ 8° and ∆ 11° with various parameters associated with solvent media at 25° has been examined. The mean activity coefficient of hydrochloric acid has been calculated