OnlineCBT
Chemistry · THERMODYNAMICS
हिन्दीCalculate \( \Delta_r H^\ominus \) for the reaction: \( \text{Fe}_2\text{O}_3(s) + 3\text{H}_2(g) \to 2\text{Fe}(s) + 3\text{H}_2\text{O}(l) \). Given: \( \Delta_f H^\ominus(\text{H}_2\text{O}, l) = -285.83\text{ kJ mol}^{-1} \) and \( \Delta_f H^\ominus(\text{Fe}_2\text{O}_3, s) = -824.2\text{ kJ mol}^{-1} \).
Correct answer · Option 3
\( -33.3\text{ kJ mol}^{-1} \)
Explanation
\( \Delta_r H^\ominus = 3\Delta_f H^\ominus(\text{H}_2\text{O}) - \Delta_f H^\ominus(\text{Fe}_2\text{O}_3) = 3(-285.83) - (-824.2) = -857.5 + 824.2 = -33.3\text{ kJ mol}^{-1} \).
