---
title: "A student compares two structural models for benzene, \\(\\text{C}_6\\text{H}_6\\), as shown in the diagram: Model 1 with localized alternating single and double carbon-carbon bonds, and Model 2 with a delocalized resonance hybrid. Which of the following experimental observations provides the best evidence supporting Model 2 over Model 1?"
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url: "https://nerd-notes.com/ubq/119215/"
date_modified: "2026-08-19T12:39:23+00:00"
---

# A student compares two structural models for benzene, \(\text{C}_6\text{H}_6\), as shown in the diagram: Model 1 with localized alternating single and double carbon-carbon bonds, and Model 2 with a delocalized resonance hybrid. Which of the following experimental observations provides the best evidence supporting Model 2 over Model 1?

A student compares two structural models for benzene, \(\text{C}_6\text{H}_6\), as shown in the diagram: Model 1 with localized alternating single and double carbon-carbon bonds, and Model 2 with a delocalized resonance hybrid. Which of the following experimental observations provides the best evidence supporting Model 2 over Model 1?

![A diagram showing two structural models of benzene, C6H6, side by side. Model 1 is labeled Model 1 and shows a hexagonal ring of six carbon atoms with alternating single and double carbon-carbon bonds (three C-C single bonds and three C=C double bonds), with one H atom bonded to each carbon atom. Model 2 is labeled Model 2 and shows a hexagonal ring of six carbon atoms with a dashed interior ring representing delocalized electron density across six equal carbon-carbon bonds, with one H atom bonded to each carbon atom. No other text or annotations appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1787143163-cTGRKl.jpg)

- **A.** All six carbon-carbon bonds have an identical measured length of \(139\text{ pm}\), which is intermediate between a standard \(\text{C}-\text{C}\) single bond (\(154\text{ pm}\)) and a standard \(\text{C}=\text{C}\) double bond (\(134\text{ pm}\)).
- **B.** Benzene reacts with hydrogen gas in the presence of a metal catalyst to form cyclohexane, \(\text{C}_6\text{H}_{12}\), consuming three moles of \(\text{H}_2\) for every one mole of benzene reacted.
- **C.** The six carbon atoms in the ring lie in a single geometric plane with bond angles of \(120^\circ\), consistent with \(sp^2\) hybridization at each carbon atom.
- **D.** Elemental analysis shows that benzene consists of \(92.3\%\) carbon and \(7.7\%\) hydrogen by mass, establishing an empirical formula of \(\text{CH}\).

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119215/*