Identify the limitations associated with standard electrode (reduction) potentials, 𝐸o.

Which statement best describes a fundamental limitation of standard electrode potentials $(E^{\circ})$?

Which of the following is a limitation of using standard electrode (reduction) potentials, $E^\circ$, to predict the spontaneity of a redox reaction?

A student sets up a galvanic cell using a zinc electrode in 1.0 mol L⁻¹ Zn²⁺(aq) and a copper electrode in 1.0 mol L⁻¹ Cu²⁺(aq) at 25 °C. The standard electrode potentials are E° = –0.76 V for Zn²⁺/Zn and E° = +0.34 V for Cu²⁺/Cu. When the student measures the cell potential after several hours of operation, it differs from the predicted E°cell value. Identify two limitations of standard electrode potentials that explain why the measured potential may differ from the predicted value.