Finding pH of solution knowing E°....

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SUMMARY

The discussion centers on calculating the minimum pH of a solution containing Ni2+/Ni with a standard electrode potential (E°) of -0.25V to prevent hydrogen production when a nickel bar is immersed. The relevant electrochemical reaction is 2H+ + Ni → Ni2+ + H2. Using the Nernst equation, the derived condition for the reaction to not occur is pH > 8.46, indicating that the solution must be sufficiently basic to inhibit hydrogen evolution.

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

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