The standard EMF of quantity electrode is 0.699V. The EMF of the quinhydrone electrode dipped in a solution with pH = 10 is:
The standard oxidation potential of Ni|Ni2+ electrode = 0.236 V. If this is combined with a hydrogen electrode in acid solution, at what pH of the solution will the measured emf be zero at 25 ºC. Assume [Ni2+] = 1M.