Finding pH of solution knowing E°....

[RaamGeneral]

Homework Statement

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.

Homework Equations

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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.

 

[Borek]

You don't need concentration of Ni²⁺ if the potential is given. Actually even the identity of the metal doesn't matter.

 

[RaamGeneral]

Ok, this is what I get:

-0.0591/2 * log( 1/[H⁺]² ) + 0.25 < 0 [the reaction does not occur and hydrogen is not produced]
pH > 8.46