Standard electrode potential (data page)
Data from different sources may cause table inconsistencies. For example: Cu + + e − ⇌ Cu (s) E 1 = + 0.520 V Cu 2 + + 2 e − ⇌ Cu (s) E 2 = + 0.337 V Cu 2 + + e − ⇌ Cu + E 3 = + 0.159 V {\displaystyle {\begin{alignedat}{4}&{\ce {Cu+ + e-}}&{}\rightleftharpoons {}&{\ce {Cu(s)}}&\quad \quad E_{1}=+0.520{\text{ V}}\\&{\ce {Cu^2+ + 2e-}}&{}\rightleftharpoons {}&{\ce {Cu(s)}}&\quad \quad E_{2}=+0.337{\text{ V}}\\&{\ce {Cu^2+ + e-}}&{}\rightleftharpoons {}&{\ce {Cu+}}&\quad \quad E_{3}=+0.159{\text{ V}}\end{alignedat}}} From additivity of Gibbs energies, one must have 2 ⋅ E 2 = 1 ⋅ E 1 + 1 ⋅ E 3 {\displaystyle 2\cdot E_{2}=1\cdot E_{1}+1\cdot E_{3}} But that equation does not hold exactly with the cited values.
change_case:english_lowercase