The value of $\Delta \mathrm{U}-\Delta \mathrm{H}$ for the reaction $\mathrm{Fe}_{2} \mathrm{O}_{3}(\mathrm{s})+3 \mathrm{C}(\mathrm{s}) \rightarrow 2 \mathrm{Fe}(\mathrm{s})+3 \mathrm{CO}(\mathrm{g})$ is
(a)-3RT
(b)+3 RT
(c)+RT
(d)-RT
Answer
Answer: A ✓ checked by 4AB · confidence high
Explanation
ΔU − ΔH = −Δn_gas RT = −3RT (three moles of CO gas formed from solids).