using the equations sro (s) co₂ (g) → srco₃ (s) ∆h° = -234 kj/mol 2 sr(s) o₂ (g) → 2 sro (s) ∆h° = -1184 kj/mol co₂ (g) → c(s) o₂ (g) ∆h° = 394 kj/mol