# chemistry

posted by
**ciaociao**
.

A galvanic cell consists of a Mn/Mn^2+ electrode (E° = -1.18v) and a Fe/Fe^2+ electrode (E° = -0.44v). Calculate the ratio [Mn2+]/[Fe2+] if E_cell = .78v at 25°C.

I know to use the nernst eq.

E_cell = E°_cell - RT/nF * ln(Q)

where Q is the ratio I'm looking for and I a know all of the other #s except for how to find E°_cell?