n which of the following reactions, standard reaction entropy change (ΔS°) is positive and standard Gibbs energy change (ΔG°) decreases sharply with increasing temperature?
(a) C(ᵣₐₚₕᵢₜₑ) + 1/2O₂(g) → CO(g)
(b) CO(g) + 1/2O₂(g) → CO₂(g)
(c) Mg(s) + 1/2O₂(g) → MgO(s)
(d) 1/2C(ᵣₐₚₕᵢₜₑ) + 1/2O₂(g) → 1/2CO₂(g)