The standard reduction potential for the half cell $$\ce{FeCO3_{(s)} + 2e- <=> Fe_{(s)} + CO3^2-} \quad\quad(E^o =-0.756 \text{V})$$ and the standard reduction potential for the half cell $$\ce{Fe^2+ + 2e- <=> Fe_{(s)}}\quad\quad\quad\quad\quad\quad (E^o = -0.44 \text{V})$$ are as given.

From these, I calculated the $\ce{E^o}$ for the reaction $$\ce{FeCO3_{(s)} <=> Fe^2+ + CO3^2-}\quad\quad(E^o = -0.31 \text{V})$$ How do I interpret this number because the dissolution is not a redox reaction? How do I calculate $\Delta G^o$ for the reaction since $n = 0$ in the dissolution reaction ($\Delta G^o=-R*T*\text{ln}(K)$ will not work)?

  • $\begingroup$ What? Where is Fe (0)? $\endgroup$ – Alchimista Jan 1 at 9:23
  • $\begingroup$ @Alchimista In the dissolution reaction, Fe stays in the +2 oxidation state on both sides of the equation so n = 0. $\endgroup$ – DrPepper Jan 1 at 13:04
  • $\begingroup$ I don't get it then... It is like wanting the circumference of a square or even worse. $\endgroup$ – Alchimista Jan 2 at 8:27

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