The minerals hematite (Fe2O3) and magnetite (Fe3O4) exist in equilibrium with atmospheric oxygen:
4Fe3O4 (s) + O2 (g) ⇌ 6Fe2O3 (s) Kp = 2.5 x 1087 at 298 K
a) Determine PO2, at equilibrium.
(b) Given that PO2, in air is 0.21 atm, in which direction will the reaction proceed to reach equilibrium?
(i) no change
(ii) toward products
(iii) toward reactants