Chemistry
posted by Miaow on .
Consider the decomposition of a metal oxide to its elements, where M represents a generic metal:
M2O3 (s) <=> 2M (s) + 3/2 O2 (g)
Given a delta Gf: 770 Kj for the M2O3
0 Kj for the M
0 Kj for the O2
What is the standard change in Gibbs energy for the reaction, as written, in the forward direction?
* I think 770 Kj ??
What is the equilibrium constant of this reaction, as written, in the forward direction at 298 K?
* K is products over reactants which leaves me with 0 ???
What is the equilibrium pressure of O2(g) over M(s) at 298 K?
* I honestly have no idea and am not even sure how to approach this!
Any information is greatly appreciated, thank you!

Right digits; wrong sign.
dGrxn = (n*dG products)  (dG reactants) = (0)  (770) = +770.
dG = RT*lnK
Substitute and solve for Kp.
Kp = pO2^{3/2} 
Thank you VERY much!

I still don't understand what to do after setting the K= pO2^(3/2). What do you substitute into the O2?