I'm stuck...that is i believe I've come to an impossible answer:

Question

I need to calculate the equilibrium constant

4Fe(s) + 3O2(g) --> 2Fe2O3(s)

First off: Delta G G Fe(s) = 0, G O2(g) = 0, G Fe2O3(s) = -741 (x2)
-741 (2) - 0 = -1480 = delta G of reaction
at equilibrium:

0 = (delta G rxn) + RT (lnk) or lnk = -(delta G rxn) / RT

so, lnk = 1480 / 2.478 = 598 = lnk

k = e^598 = Impossible? This would be an humongous number so I think I went astray somewhere.

Any help?