---
title: "A student evaluates a proposed thermal regeneration step that reverses the net chemistry of a sulfur-recovery process. The following standard enthalpy changes at \\(25^\\circ\\text{C}\\) are available.  | Thermochemical equation | \\(\\Delta H^\\circ\\) | |—|—:| | \\(2\\text{H}_2\\text{S(g)}+3\\text{O}_2\\text{(g)}\\rightarrow 2\\text{SO}_2\\text{(g)}+2\\text{H}_2\\text{O(l)}\\) | \\(-1124\\text{ kJ/mol}_{\\text{rxn}}\\) | | \\(\\text{S(s)}+\\text{O}_2\\text{(g)}\\rightarrow \\text{SO}_2\\text{(g)}\\) | \\(-297\\text{ kJ/mol}_{\\text{rxn}}\\) |  What is \\(\\Delta H^\\circ\\) for the proposed reaction \\(3\\text{S(s)}+2\\text{H}_2\\text{O(l)}\\rightarrow 2\\text{H}_2\\text{S(g)}+\\text{SO}_2\\text{(g)}\\)?"
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date_modified: "2026-08-19T12:40:30+00:00"
---

# A student evaluates a proposed thermal regeneration step that reverses the net chemistry of a sulfur-recovery process. The following standard enthalpy changes at \(25^\circ\text{C}\) are available.

| Thermochemical equation | \(\Delta H^\circ\) |
|—|—:|
| \(2\text{H}_2\text{S(g)}+3\text{O}_2\text{(g)}\rightarrow 2\text{SO}_2\text{(g)}+2\text{H}_2\text{O(l)}\) | \(-1124\text{ kJ/mol}_{\text{rxn}}\) |
| \(\text{S(s)}+\text{O}_2\text{(g)}\rightarrow \text{SO}_2\text{(g)}\) | \(-297\text{ kJ/mol}_{\text{rxn}}\) |

What is \(\Delta H^\circ\) for the proposed reaction \(3\text{S(s)}+2\text{H}_2\text{O(l)}\rightarrow 2\text{H}_2\text{S(g)}+\text{SO}_2\text{(g)}\)?

A student evaluates a proposed thermal regeneration step that reverses the net chemistry of a sulfur-recovery process. The following standard enthalpy changes at \(25^\circ\text{C}\) are available.

| Thermochemical equation | \(\Delta H^\circ\) |
|---|---:|
| \(2\text{H}_2\text{S(g)}+3\text{O}_2\text{(g)}\rightarrow 2\text{SO}_2\text{(g)}+2\text{H}_2\text{O(l)}\) | \(-1124\text{ kJ/mol}_{\text{rxn}}\) |
| \(\text{S(s)}+\text{O}_2\text{(g)}\rightarrow \text{SO}_2\text{(g)}\) | \(-297\text{ kJ/mol}_{\text{rxn}}\) |

What is \(\Delta H^\circ\) for the proposed reaction \(3\text{S(s)}+2\text{H}_2\text{O(l)}\rightarrow 2\text{H}_2\text{S(g)}+\text{SO}_2\text{(g)}\)?

- **A.** \(-233\text{ kJ/mol}_{\text{rxn}}\)
- **B.** \(+233\text{ kJ/mol}_{\text{rxn}}\)
- **C.** \(+827\text{ kJ/mol}_{\text{rxn}}\)
- **D.** \(+2015\text{ kJ/mol}_{\text{rxn}}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119456/*