---
title: "A student investigates the relationship between bond order, bond length, and bond enthalpy for the carbon-carbon bonds in ethane (\\(\\text{C}_2\\text{H}_6\\)), ethene (\\(\\text{C}_2\\text{H}_4\\)), and ethyne (\\(\\text{C}_2\\text{H}_2\\)). Which of the following correctly ranks the carbon-carbon bond enthalpy from greatest to least, and provides the correct justification?"
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url: "https://nerd-notes.com/ubq/119827/"
date_modified: "2026-08-21T08:12:34+00:00"
---

# A student investigates the relationship between bond order, bond length, and bond enthalpy for the carbon-carbon bonds in ethane (\(\text{C}_2\text{H}_6\)), ethene (\(\text{C}_2\text{H}_4\)), and ethyne (\(\text{C}_2\text{H}_2\)). Which of the following correctly ranks the carbon-carbon bond enthalpy from greatest to least, and provides the correct justification?

A student investigates the relationship between bond order, bond length, and bond enthalpy for the carbon-carbon bonds in ethane (\(\text{C}_2\text{H}_6\)), ethene (\(\text{C}_2\text{H}_4\)), and ethyne (\(\text{C}_2\text{H}_2\)). Which of the following correctly ranks the carbon-carbon bond enthalpy from greatest to least, and provides the correct justification?

- **A.** \(\text{C}_2\text{H}_6 > \text{C}_2\text{H}_4 > \text{C}_2\text{H}_2\), because single bonds are longer and have greater electron density between the carbon nuclei than multiple bonds.
- **B.** \(\text{C}_2\text{H}_6 > \text{C}_2\text{H}_4 > \text{C}_2\text{H}_2\), because longer bonds require more energy to overcome the attractive forces between the bonded atoms.
- **C.** \(\text{C}_2\text{H}_2 > \text{C}_2\text{H}_4 > \text{C}_2\text{H}_6\), because the triple bond in \(\text{C}_2\text{H}_2\) is the longest bond and has the weakest nuclear repulsion.
- **D.** \(\text{C}_2\text{H}_2 > \text{C}_2\text{H}_4 > \text{C}_2\text{H}_6\), because the triple bond in \(\text{C}_2\text{H}_2\) shares three pairs of electrons, resulting in a shorter bond and stronger electrostatic attraction between the nuclei and shared electrons.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119827/*