Does standard reduction potential depend on temperature?

I am confused because my institute gives the definition for standard reduction potential as the potential that is measured at standard state which defines as measured in atmospheric pressure at $\pu{298 K}$, and when the concentration of all the substances is unity. But as far as my understanding goes standard states can be defined at any temperature and not just $\pu{298 K}$.
Also, as its directly related to $\Delta G^\circ = -nFE_\mathrm{cell} = \Delta H^\circ - T\Delta S^\circ$, this points toward it being dependent on temperature. Also, when someone says standard state, does that put restriction on temperature being $\pu{298 K}$??

  • $\begingroup$ Yes, see the Nernst Equation. $\endgroup$ – MaxW Jun 18 '20 at 19:27
  • $\begingroup$ @MaxW Thank You, but I still don't get it, how does nerst equation help ?? Like all it does is relate electrode potential to standard electrode potential , it says that the electrode potential will depend on temperature, but nothing about the standard electrode potential $\endgroup$ – Manish Mittal Jun 18 '20 at 20:40
  • 1
    $\begingroup$ I think I disagree with @MaxW here, but it's really over semantics, not over the substance of his point. The standard potential is standard. If you have a non-standard state, then you have a different value. In other words, the standard value is constant, but the actual electrode potential definitely depends on temperature. $\endgroup$ – Zhe Jun 18 '20 at 20:40
  • $\begingroup$ @Zhe Does the standard state mean it's only at 298 K ?? $\endgroup$ – Manish Mittal Jun 18 '20 at 20:41
  • 1
    $\begingroup$ The standard state is 298 K. I would not expect the potential to be the same if you change the temperature... $\endgroup$ – Zhe Jun 18 '20 at 20:57

Yes, the standard reduction potential does depend on temperature. The definition of the standard reduction potential is stated in Ref.1 as:

A standard electrode potential $E^\circ$ is defines as the potential (in Volts, $\pu{V}$) of a half-reaction relative to a reference electrode at a specific temperature, all chemicals being at their standard states at unit activity. These states may be arbitrarily defined as pure crystalline solids, pure liquids, ideal gases at one atmosphere fugacity ($\pu{101325 \times 10^{5} Pa}$), and ideal solutes at unit molality. The most common temperature for the tabulation of standard electrode potentials, as for their thermodynamic data, is $\pu{25 ^\circ C}$ ($\pu{298.15 K}$).

Accordingly, tabulated data is chosen to be at $\pu{298.15 K}$ for the convenience. This is also beneficial that the most common reference electrode is the Standard Hydrogen Electrode (SHE) for the solvent water:

$$\ce{2H+_{(aq)} + 2e- <=> H2_{(g)}} \tag1$$

$E^\circ_{(\ce{H+/H2})}$ for the above half-reaction is been assigned as zero volts at all temperatures. Extended work over $\pu{298.15 K}$ by De Béthune and coworkers shown that the temperature dependence of $E^\circ$ is approximately linear between $\pu{273.15 K}$ and $\pu{373.15 K}$ according to the following equation (Ref.2-Ref.4):

$$E_T = E^\circ_{298} + (T - 298.15)\left(\frac{dE^\circ}{dT}\right)_{298} \tag2$$


  1. Steven G. Bratsch, “Standard Electrode Potentials and Temperature Coefficients in Water at $\pu{298.15 K}$,” Journal of Physical and Chemical Reference Data 1989, 18(1), 1-21 (https://doi.org/10.1063/1.555839).
  2. A. J. De Béthune, T. S. Licht, N. Swendeman, “The Temperature Coefficients of Electrode Potentials: The Isothermal and Thermal Coefficients—The Standard Ionic Entropy of Electrochemical Transport of the Hydrogen Ion,” Journal of The Electrochemical Society 1959, 106(7), 616 (doi:10.1149/1.2427448).
  3. G. R. Salvi, A. J. De Béthune, “The Temperature Coefficients of Electrode Potentials: II. The Second Isothermal Temperature Coefficient,” Journal of The Electrochemical Society 1961, 108(7), 672 (doi: 10.1149/1.2428187).
  4. André Jacques De Béthune, Nancy A. Swendeman Loud, In Standard Aqueous Electrode Potentials and Temperature Coefficients at $\pu{25 ^\circ C}$; C. A. Hampel: Skokie, ILL, 1964.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.