What is the relation between standard Gibbs free energy change Delta G^\circ and standard cell EMF E^\circ_cell?
Answer and explanation
Correct answer: C. Delta G^\circ = -n F E^\circ_cell
- Step 1: Maximum electrical work done by a cell is w_elec = q E = n F E^\circ_cell. Step 2. Since Delta G = -w_elec, standard Gibbs energy change is Delta G^\circ = -n F E^\circ_cell. A positive cell EMF corresponds to a spontaneous negative Delta G. Answer: Delta G^\circ = -n F E^\circ_cell. Why not the others: Positive sign would violate spontaneity for galvanic cells; division by n is wrong; division by E is dimensionally invalid.
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