1. The problem statement, all variables and given/known data The reduction of O2 to H2O in acidic solution has a standard reduction potential of +1.23 V. What is the effect on the half-cell potential at 25 °C when the pH of the solution is increased by one unit? O2(g) + 4H+(aq) + 4e- –> 2 H2O(l) (A) The half-cell potential decreases by 59 mV. (B) The half-cell potential increases by 59 mV. (C) The half-cell potential decreases by 236 mV. (D) The half-cell potential increases by 236 mV. 2. Relevant equations Nernst Equation 3. The attempt at a solution I'm aware this is a Nernst equation problem. Yet, I'm not exactly sure how to apply it. It appears to me that the reaction quotient would be 0, since there is only a pure liquid on the product side. As such, I am not sure how to approach the problem.