1. The problem statement, all variables and given/known data The pair Ni2+/Ni has E°=-0.25V. Find the minimum pH of the sulution so that a nickel bar immersed in it, doesn't produce hydrogen. 2. Relevant equations - 3. The attempt at a solution This problem doesn't make any sense to me. Maybe there is a cell in which the following reaction occurs: 2H+ + Ni ---> Ni2+ + H2 I thought I could use something like the Nernts equation but I don't know [Ni2+]. I need some guidance. Thank you.