The Dependence of Aqueous Sulfur‐Polysulfide Redox Potential on Electrolyte Composition and Temperature

Literature data for the redox potential of the aqueous sulfur‐polysulfide redox couple have been correlated by accounting for the complex equilibration of various sulfur‐bearing species in alkaline electrolyte. For electrolytes wherein the ratio of zero‐valent sulfur to total sulfide ranges from 0.1 to 3.0, the pH ranges from 10.6 to 13.8, and the temperature ranges from 25 to 90°C, the redox potential is correlated by the expression This equation represents the redox potentials to within 2% at all compositions and temperatures, except for the electrolyte with a ratio of 3.0 at 80°C, for which the deviation is 6%.