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title: "The standard molar enthalpy of formation, \\(\\Delta H_f^\\circ\\), is defined as the enthalpy change that occurs when \\(1\\text{ mol}\\) of a pure compound is formed from its constituent elements in their standard states at \\(298\\text{ K}\\) and \\(1\\text{ atm}\\). Which of the following balanced chemical equations represents the process corresponding to \\(\\Delta H_f^\\circ\\) for liquid ethanol, \\(\\text{C}_2\\text{H}_5\\text{OH}(l)\\)?"
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url: "https://nerd-notes.com/ubq/119931/"
date_modified: "2026-08-21T08:18:26+00:00"
---

# The standard molar enthalpy of formation, \(\Delta H_f^\circ\), is defined as the enthalpy change that occurs when \(1\text{ mol}\) of a pure compound is formed from its constituent elements in their standard states at \(298\text{ K}\) and \(1\text{ atm}\). Which of the following balanced chemical equations represents the process corresponding to \(\Delta H_f^\circ\) for liquid ethanol, \(\text{C}_2\text{H}_5\text{OH}(l)\)?

The standard molar enthalpy of formation, \(\Delta H_f^\circ\), is defined as the enthalpy change that occurs when \(1\text{ mol}\) of a pure compound is formed from its constituent elements in their standard states at \(298\text{ K}\) and \(1\text{ atm}\). Which of the following balanced chemical equations represents the process corresponding to \(\Delta H_f^\circ\) for liquid ethanol, \(\text{C}_2\text{H}_5\text{OH}(l)\)?

- **A.** \(4\text{ C(s)} + 6\text{ H}_2\text{(g)} + \text{O}_2\text{(g)} \rightarrow 2\text{ C}_2\text{H}_5\text{OH}(l)\)
- **B.** \(2\text{ CO}_2\text{(g)} + 3\text{ H}_2\text{O}(l) \rightarrow \text{C}_2\text{H}_5\text{OH}(l) + 3\text{ O}_2\text{(g)}\)
- **C.** \(2\text{ C(s)} + 3\text{ H}_2\text{(g)} + \dfrac{1}{2}\text{ O}_2\text{(g)} \rightarrow \text{C}_2\text{H}_5\text{OH}(l)\)
- **D.** \(2\text{ C(g)} + 6\text{ H(g)} + \text{O(g)} \rightarrow \text{C}_2\text{H}_5\text{OH}(l)\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119931/*