Answer:
K = [Fe]4×[CO2] / [Fe2O3]2 × [C]6 × [O2]3
Explanation: the over all reaction is
2Fe2O3(s) + 6C(s) + 3O2(g) ---> 4Fe(I) + 6CO2 (g)
So equilibrium constant equals, product concentration/ reactant concentration.
K = [Fe]4×[CO2] / [Fe2O3]2 × [C]6 × [O2]3