Given reaction, Fe.0s(s)+3H2(g)⟶3H,O(r)+2Fe(s) and ‌‌H1∘(H,O)=−28600kj∕mol H10(Fe,O3)=−824kJ∕mol Therefore. Hp (Heat of reaction) =ΣH1∘(products) −ΣH1* (reactants) HR=−(3×286)−(−824) ∵(Hf for H2 and Fe=0) HA=−858+824 HA=−34kj∕mol