Which of the following properties properly distinguish standard Gibbs free energy () and the standar — Electrochemistry Chemistry Question
Question
Which of the following properties properly distinguish standard Gibbs free energy ($\Delta G^\circ$) and the standard cell potential ($E^\circ_{cell}$) in electrochemistry?
💡 Solution & Explanation
Gibbs free energy ($\Delta G^\circ$) is an extensive state function; its value depends directly on the number of moles reacting. Conversely, $E^\circ_{cell}$ is intensive; it is a measure of potential difference, not total energy, and remains constant regardless of stoichiometric scaling. Because $E^\circ$ is intensive, $E^\circ$ values cannot be algebraically added when combining half-cells; one must convert them to $\Delta G^\circ$, sum the energies, and convert back. Spontaneity is confirmed when $\Delta G^\circ < 0$ and $E^\circ_{cell} > 0$.