The Gibbs free-energy change of a galvanic cell reaction is given by:
- $\Delta G = -E/(nF)$
- $\Delta G = +nFE$
- $\Delta G = -nFE$
- $\Delta G = nF/E$
Show answer and solution
Correct answer: C. $\Delta G = -nFE$
$\Delta G = -nFE$, where $n$ = number of electrons transferred, $F$ = Faraday constant (96 485 C/mol), $E$ = cell EMF.
A positive $E$ ⇒ negative $\Delta G$ ⇒ spontaneous reaction.