---
title: "A student investigates the physical properties of four unbranched alkanes: methane (\\(\\text{CH}_4\\)), ethane (\\(\\text{C}_2\\text{H}_6\\)), propane (\\(\\text{C}_3\\text{H}_8\\)), and butane (\\(\\text{C}_4\\text{H}_{10}\\)). Which of the following lists the four compounds in order of increasing normal boiling point and provides the correct justification?"
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url: "https://nerd-notes.com/ubq/119927/"
date_modified: "2026-08-21T08:18:15+00:00"
---

# A student investigates the physical properties of four unbranched alkanes: methane (\(\text{CH}_4\)), ethane (\(\text{C}_2\text{H}_6\)), propane (\(\text{C}_3\text{H}_8\)), and butane (\(\text{C}_4\text{H}_{10}\)). Which of the following lists the four compounds in order of increasing normal boiling point and provides the correct justification?

A student investigates the physical properties of four unbranched alkanes: methane (\(\text{CH}_4\)), ethane (\(\text{C}_2\text{H}_6\)), propane (\(\text{C}_3\text{H}_8\)), and butane (\(\text{C}_4\text{H}_{10}\)). Which of the following lists the four compounds in order of increasing normal boiling point and provides the correct justification?

- **A.** \(\text{CH}_4 < \text{C}_2\text{H}_6 < \text{C}_3\text{H}_8 < \text{C}_4\text{H}_{10}\), because as the number of electrons increases, the electron cloud becomes more polarizable, resulting in stronger London dispersion forces.
- **B.** \(\text{CH}_4 < \text{C}_2\text{H}_6 < \text{C}_3\text{H}_8 < \text{C}_4\text{H}_{10}\), because larger molecules contain a greater number of covalent bonds that require more energy to break during boiling.
- **C.** \(\text{C}_4\text{H}_{10} < \text{C}_3\text{H}_8 < \text{C}_2\text{H}_6 < \text{CH}_4\), because smaller molecules have a higher charge density that allows them to form stronger dipole-dipole attractions.
- **D.** \(\text{C}_4\text{H}_{10} < \text{C}_3\text{H}_8 < \text{C}_2\text{H}_6 < \text{CH}_4\), because smaller molecules have less surface area, allowing them to pack more tightly and form stronger intermolecular attractions.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119927/*