Oxidation-Reduction Indicators

IndicatorE°, VColor, Reduced-Oxidized Forms
Methylene blue 0.26 C-B
Diphenylamine 0.76 C-V
Sodium diphenylbenzidine sulfonate 0.87 C-V
Erioglaucine A 1.00 G-R
Tris(1,10-phenanthroline)iron(II) sulfate 1.06 R-B
Tris(5-nitro-1,10-phenanthroline)iron(II) sulfate 1.25 R-B

Reference: I.M. Kolthoff and V.A. Stenger, "Volumetric Analysis," 2nd ed., Vol. 1, Interscience, NY, 1942, p. 140.