What is the cell potential of the following cell at 25 oC? Note Pt is a passive electrode.?

Question

What is the cell potential of the following cell at 25 degree C? Note Pt is a passive electrode.

Pt / H2 (0.67 atm), H1+ (0.032 M) // Hg2+ (0.58 M) / Hg

Answer 1

The standard reduction potentials related:
Hg(2+)(aq) + 2e- ==> Hg(l), Eo = +0.854V
2H+(aq) + 2e- ==> H2(g), Eo = 0.00V
Thus: Hg(2+)(aq) + H2(g) ==> Hg(l) + 2H+(aq), Eo = +0.854V

Using Nernst equation:
E = E° + (0.0591/n)*log([Hg2+]*P(H2)/[H+]^2)
= 0.854+(0.0591/2)*log(0.58*0.67/0.032^2)
= 0.93V