The oxidation of copper(I) oxide, Cu2O(s) , to copper(II) oxide, CuO(s) , is an exothermic process.

Question

2Cu2O(s)+O2(g)⟶4CuO(s)

The change in enthalpy upon reaction of 70.64 g Cu2O(s) is −72.08 kJ .

Calculate the work, 𝑤 , and energy change, Δ𝑈rxn , when 70.64 g Cu2O(s) is oxidized at a constant pressure of 1.00 bar and a constant temperature of 25∘ C .

Note that Δ𝐸rxn is sometimes used as the symbol for energy change instead of Δ𝑈rxn .