[nicnac89]

The question is:

In a solution, the concentrations of Eu^3+ and Eu^2+ are 2.5 x 10^-2 mol dm^-3 and 2.5 x 10^-3 mol dm^-3 respectively.  Given that the standard potential for the Eu^3+/Eu^2+ redox reaction is -0.43V, determine the equilibrium potential for the system.

I'm guessing you use:

E = RT/nF ln (Eu^2+/Eu^3+)

but after that I'm not sure where the -0.43V (standard potential) comes into it...do you subtract the answer from this?

That's really just a stab in the dark so any help will be much appreciated!

[Borek]

Nernst equation doesn't look the way you posted it.