The minerals hematite (Fe₂O₃) and magnetite (Fe₃O₄) exist in equilibrium with atmospheric oxygen: 4Fe₃O₄(s)+O₂(g)⇌6Fe₂O₃(s).Kp=2.5×10⁸⁷ at 298 K.
a) Determine 2PO₂ at equilibrium.
b) 2.5×10⁸⁷
c) 2.5×10⁻⁸⁷
d) 2.5×10⁴³