For an arbitrary spontaneous electrochemical reaction, which of the following sets of thermodynamic — Electrochemistry Chemistry Question
Question
For an arbitrary spontaneous electrochemical reaction, which of the following sets of thermodynamic and equilibrium signs is strictly CORRECT? ($\Delta G^\circ$ is standard free energy change, $K$ is equilibrium constant, $E^\circ_{cell}$ is standard cell potential)
💡 Solution & Explanation
For a spontaneous chemical reaction under standard states, the standard Gibbs free energy change must be negative ($\Delta G^\circ < 0$). Because $\Delta G^\circ = -nFE^\circ_{cell}$, a negative free energy mandates a positive standard cell potential ($E^\circ_{cell} > 0$). Furthermore, since $\Delta G^\circ = -RT \ln K$, a negative $\Delta G^\circ$ requires $\ln K > 0$, meaning the equilibrium constant $K$ must be greater than $1$.