The minerals hematite (Fe₂O₃) and magnetite (Fe₃O₄) exist in equilibrium with atmospheric oxygen: 4Fe₃O₄(s) + O₂(g) ⇄ 6Fe₂O₃(s) Kp = 2.5×10⁸⁷ at 298K(b) Given that PO₂ in air is 0.21 atm, in which direction will the reaction proceed to reach equilibrium?
