---
title: "The thermal decomposition of calcium carbonate is represented by the equation below.  \\[ \\text{CaCO}_3(s) \\rightleftharpoons \\text{CaO}(s) + \\text{CO}_2(g) \\]  For this reaction, \\(\\Delta H^\\circ = +176\\text{ kJ/mol}_{\\text{rxn}}\\) and \\(\\Delta S^\\circ = +160\\text{ J/}(\\text{mol}_{\\text{rxn}}\\cdot\\text{K})\\). Assuming that \\(\\Delta H^\\circ\\) and \\(\\Delta S^\\circ\\) are constant over the temperature range, at approximately what temperature does the reaction transition from thermodynamically unfavorable to thermodynamically favorable under standard conditions?"
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url: "https://nerd-notes.com/ubq/120325/"
date_modified: "2026-08-23T04:23:07+00:00"
---

# The thermal decomposition of calcium carbonate is represented by the equation below.

\[ \text{CaCO}_3(s) \rightleftharpoons \text{CaO}(s) + \text{CO}_2(g) \]

For this reaction, \(\Delta H^\circ = +176\text{ kJ/mol}_{\text{rxn}}\) and \(\Delta S^\circ = +160\text{ J/}(\text{mol}_{\text{rxn}}\cdot\text{K})\). Assuming that \(\Delta H^\circ\) and \(\Delta S^\circ\) are constant over the temperature range, at approximately what temperature does the reaction transition from thermodynamically unfavorable to thermodynamically favorable under standard conditions?

The thermal decomposition of calcium carbonate is represented by the equation below.

\[ \text{CaCO}_3(s) \rightleftharpoons \text{CaO}(s) + \text{CO}_2(g) \]

For this reaction, \(\Delta H^\circ = +176\text{ kJ/mol}_{\text{rxn}}\) and \(\Delta S^\circ = +160\text{ J/}(\text{mol}_{\text{rxn}}\cdot\text{K})\). Assuming that \(\Delta H^\circ\) and \(\Delta S^\circ\) are constant over the temperature range, at approximately what temperature does the reaction transition from thermodynamically unfavorable to thermodynamically favorable under standard conditions?

- **A.** \(1.10\text{ K}\)
- **B.** \(1{,}100\text{ K}\)
- **C.** \(1{,}370\text{ K}\)
- **D.** \(11{,}000\text{ K}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/120325/*