To raise the Nernst-predicted cell potential, which combination is effective?

• A. Increase the cathode potential and decrease the anode potential, and adjust concentrations to favor larger Ecell.
• B. Use a less positive cathode and a more positive anode to increase driving force.
• C. Keep concentrations equal to the standard state.
• D. Increase the temperature only.

Answer: (B)

The main idea is that the cell potential from the Nernst equation is set by the difference between the cathode’s tendency to gain electrons and the anode’s tendency to lose electrons, with the concentration term (the reaction quotient) shifting that value as well. To raise the Nernst-predicted cell potential, you want a larger driving force—that is, a larger effective difference in electrode tendencies.

Choosing a cathode that is less positive in reduction potential while pairing it with an anode that has a more positive reduction potential increases the overall driving force for electron flow in the cell’s favored direction, which raises the calculated Ecell according to the Nernst relationship. The other approaches either keep the electrode tendencies more similar, rely only on temperature without guaranteeing a higher potential, or keep concentrations at standard state, which does not systematically raise Ecell.