Iron(III) oxide reacts with carbon monoxide according to the equation: Fe₂O₃(s) + 3 CO(g) → 2 Fe(s) + 3 CO₂(g) A reaction mixture initially contains 22.55 g Fe₂O₃ and 14.78 g CO. Once the reaction has occurred as completely as possible, what mass (in g) of the excess reactant remains?