Calculate for the following reaction at 298 K:<br><br>from the following thermochemical equations:<b — Thermodynamics and Thermochemistry Chemistry Question
Question
Calculate $\Delta H$ for the following reaction at 298 K:<br>$\text{Fe}_2\text{O}_3\text{(s)} + 3\text{CO(g)} \to 2\text{Fe(s)} + 3\text{CO}_2\text{(g)}$<br>from the following thermochemical equations:<br>(i) $3\text{Fe}_2\text{O}_3\text{(s)} + \text{CO(g)} \to 2\text{Fe}_3\text{O}_4\text{(s)} + \text{CO}_2\text{(g)}; \Delta H = -46.4\text{ kJ}$<br>(ii) $\text{FeO(s)} + \text{CO(g)} \to \text{Fe(s)} + \text{CO}_2\text{(g)}; \Delta H = 9.0\text{ kJ}$<br>(iii) $\text{Fe}_3\text{O}_4\text{(s)} + \text{CO(g)} \to 3\text{FeO(s)} + \text{CO}_2\text{(g)}; \Delta H = -41.0\text{ kJ}$
💡 Solution & Explanation
Target reaction is obtained by linear combination: $1/3 \times \text{Eq(i)} + 2/3 \times \text{Eq(iii)} + 2 \times \text{Eq(ii)}$. $\Delta H = 1/3(-46.4) + 2/3(-41.0) + 2(9.0) = -15.467 - 27.333 + 18.0 = -42.8 + 18.0 = -24.8\text{ kJ}$.