Electrochemistry lab tool
Convert a redox potential measured against one reference electrode to the corresponding value against another reference scale.
For CH3CN at 25 °C. Conversion constants from Pavlishchuk and Addison.
Inputs
Potential and reference electrodes
Result
Converted potential
Enter a potential
Conversion
Enter a potential and select two reference electrodes.
Scope and comparability
These constants apply to acetonitrile (CH₃CN) at 25 °C with 0.1 M tetraethylammonium perchlorate (TEAP) or tetraethylammonium hexafluorophosphate (Et₄NPF₆) supporting electrolyte, with or without a bridge. These conversions are literature-based approximations. Experimental reference potentials depend on solvent, electrolyte, concentration, temperature, junction design and measurement convention. The source gives ±10 mV as approximate interlaboratory comparability under its stated conditions, not as an accuracy guarantee.
Method
Reference-scale conversion
The converter applies the tabulated offset between the selected reference scales: Eto = Efrom + ΔEto−from. It does not convert formal potentials between solvents or experimental conditions.
Worked example
Under the stated acetonitrile conditions, 0.000 V versus SCE corresponds to approximately −0.380 V versus Fc⁺/Fc.
Use with care: report the solvent, supporting electrolyte, temperature, reference-electrode construction, and whether an internal standard was used.
Constants used
Internal offsets
| Code | Reference electrode | Composition | Offset (mV) |
|---|---|---|---|
| ANE1 | Ag+/Ag | 0.1 M AgNO3 | 0 |
| ANE2 | Ag+/Ag | 0.01 M AgNO3 | +45 |
| ANE3 | Ag+/Ag | 0.001 M AgNO3 | +97 |
| APE | Ag+/Ag | 0.01 M AgClO4 | +47 |
| Fc | Fc+/Fc | Internal reference couple | −37 |
| NHE | Normal hydrogen electrode | Defined reference scale | +593 |
| SCE | Saturated calomel electrode | Saturated KCl | +343 |
| SSCE | Saturated sodium calomel electrode | Saturated NaCl | +347 |
| SHE | Standard hydrogen electrode | Defined reference scale | +587 |
Offsets are the internal values used by the converter. The difference between the destination and source offsets is added to the entered potential.
Tool version 1.2, released 21 July 2026. V. V. Pavlishchuk and A. W. Addison, “Conversion Constants for Redox Potentials Measured versus Different Reference Electrodes in Acetonitrile Solutions at 25 °C”, Inorganica Chimica Acta 298 (2000), 97–102. doi:10.1016/S0020-1693(99)00407-7. The 2025 corrigendum corrects the ferrocene-experiment supporting-electrolyte concentration from 0.01 M to 0.1 M; this tool states the corrected concentration.