---
title: "A student evaluates two fuels, fuel \\(\\text{X}\\) and fuel \\(\\text{Y}\\), for use in a portable stove. The molar mass and standard enthalpy of combustion, \\(\\Delta H^\\circ_{\\text{comb}}\\), for each fuel are provided in the table below.  | Fuel | Molar mass (\\(\\text{g/mol}\\)) | \\(\\Delta H^\\circ_{\\text{comb}}\\) (\\(\\text{kJ/mol}_{\\text{rxn}}\\)) | | :— | :— | :— | | \\(\\text{X}\\) | \\(60.0\\) | \\(-1200\\) | | \\(\\text{Y}\\) | \\(30.0\\) | \\(-1800\\) |  Assuming complete combustion under standard conditions, which of the following represents the ratio of the heat released by the combustion of \\(1.00 \\text{ g}\\) of fuel \\(\\text{Y}\\) to the heat released by the combustion of \\(1.00 \\text{ g}\\) of fuel \\(\\text{X}\\), \\(\\dfrac{q_{\\text{Y}}}{q_{\\text{X}}}\\)?"
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url: "https://nerd-notes.com/ubq/121502/"
date_modified: "2026-08-23T05:04:51+00:00"
---

# A student evaluates two fuels, fuel \(\text{X}\) and fuel \(\text{Y}\), for use in a portable stove. The molar mass and standard enthalpy of combustion, \(\Delta H^\circ_{\text{comb}}\), for each fuel are provided in the table below.

| Fuel | Molar mass (\(\text{g/mol}\)) | \(\Delta H^\circ_{\text{comb}}\) (\(\text{kJ/mol}_{\text{rxn}}\)) |
| :— | :— | :— |
| \(\text{X}\) | \(60.0\) | \(-1200\) |
| \(\text{Y}\) | \(30.0\) | \(-1800\) |

Assuming complete combustion under standard conditions, which of the following represents the ratio of the heat released by the combustion of \(1.00 \text{ g}\) of fuel \(\text{Y}\) to the heat released by the combustion of \(1.00 \text{ g}\) of fuel \(\text{X}\), \(\dfrac{q_{\text{Y}}}{q_{\text{X}}}\)?

A student evaluates two fuels, fuel \(\text{X}\) and fuel \(\text{Y}\), for use in a portable stove. The molar mass and standard enthalpy of combustion, \(\Delta H^\circ_{\text{comb}}\), for each fuel are provided in the table below.

| Fuel | Molar mass (\(\text{g/mol}\)) | \(\Delta H^\circ_{\text{comb}}\) (\(\text{kJ/mol}_{\text{rxn}}\)) |
| :--- | :--- | :--- |
| \(\text{X}\) | \(60.0\) | \(-1200\) |
| \(\text{Y}\) | \(30.0\) | \(-1800\) |

Assuming complete combustion under standard conditions, which of the following represents the ratio of the heat released by the combustion of \(1.00 \text{ g}\) of fuel \(\text{Y}\) to the heat released by the combustion of \(1.00 \text{ g}\) of fuel \(\text{X}\), \(\dfrac{q_{\text{Y}}}{q_{\text{X}}}\)?

- **A.** \(0.33\)
- **B.** \(0.75\)
- **C.** \(1.5\)
- **D.** \(3.0\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/121502/*