Verified Solution • 2025–26 Session moderate

QJEEM24Chd55c: JEE Main 2024 Chemistry - Class 11 JEEM24Chd55c Solution: Two reactions are given below: Then enthalpy change for…

Two reactions are given below:

amp;2Fe(s)+32O2( g)→Fe2O3( s),ΔH∘=−822 kJ/molamp;C(s)+12O2( g)→CO(g),ΔH∘=−110 kJ/mol\begin{aligned}& 2 \mathrm{Fe}_{(\mathrm{s})}+\frac{3}{2} \mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{Fe}_2 \mathrm{O}_{3(\mathrm{~s})}, \Delta \mathrm{H}^{\circ}=-822 \mathrm{~kJ} / \mathrm{mol} \\& \mathrm{C}_{(\mathrm{s})}+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{CO}_{(\mathrm{g})}, \Delta \mathrm{H}^{\circ}=-110 \mathrm{~kJ} / \mathrm{mol}\end{aligned}

Then enthalpy change for following reaction 3C(s)+Fe2O3( s)→2Fe(s)+3CO(g)3 \mathrm{C}_{(\mathrm{s})}+\mathrm{Fe}_2 \mathrm{O}_{3(\mathrm{~s})} \rightarrow 2 \mathrm{Fe}_{(\mathrm{s})}+3 \mathrm{CO}_{(\mathrm{g})} is _______ kJ/mol\mathrm{kJ} / \mathrm{mol} .

Step-by-Step Verified Solution

2Fe(s)+32O2( g)→Fe2O3( s),ΔH∘=−822 kJ/mol2 \mathrm{Fe}_{(\mathrm{s})}+\frac{3}{2} \mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{Fe}_2 \mathrm{O}_{3(\mathrm{~s})}, \Delta \mathrm{H}^{\circ}=-822 \mathrm{~kJ} / \mathrm{mol} ........ (1)

C(s)+12O2( g)→CO(g),ΔH∘=−110 kJ/mol\mathrm{C}_{(\mathrm{s})}+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{CO}_{(\mathrm{g})}, \Delta \mathrm{H}^{\circ}=-110 \mathrm{~kJ} / \mathrm{mol} ........ (2)

3C(s)+Fe2O3( s)→2Fe(s)+3CO(g),ΔH3= ? 3 \mathrm{C}_{(\mathrm{s})}+\mathrm{Fe}_2 \mathrm{O}_{3(\mathrm{~s})} \rightarrow 2 \mathrm{Fe}_{(\mathrm{s})}+3 \mathrm{CO}_{(\mathrm{g})}, \Delta \mathrm{H}_3=\text { ? }

amp;(3)=3×(2)−(1)amp;ΔH3amp;=3×ΔH2−ΔH1amp;=3(−110)+822amp;=492 kJ/mole\begin{aligned}& (3)=3 \times(2)-(1) \\& \begin{aligned}\Delta \mathrm{H}_3 & =3 \times \Delta \mathrm{H}_2-\Delta \mathrm{H}_1 \\& =3(-110)+822 \\& =492 \mathrm{~kJ} / \mathrm{mole}\end{aligned}\end{aligned}

Related Learning Resources & Exam Preparation