Calculate the standard change in gibbs free energy of the following reactions at standard ambient temperature and pressure (satp) and label them as spontaneous or nonspontaneous.
a. CO(g) + O₂ ↔ 2CO₂(g); ∆Hᵒ = -566.0 kJ, ∆Sᵒ = -173.0 J/K
∆Gᵒ = ___________ kJ, and the reaction is ______________.