The oxidation of copper(I) oxide, Cu₂O(s) , to copper(II) oxide, CuO(s) , is an exothermic process. 2Cu₂O(s) + O₂(g) ⟶ 4CuO(s) ΔH∘rxn = −292. 0 kJ mol Calculate the energy released as heat When 54. 08 g Cu₂O ( s ) undergo oxidation at constant pressure.