---
title: "A sample of a non-stoichiometric iron oxide compound has the empirical formula \\(\\text{Fe}_{0.80}\\text{O}\\). The solid consists of a crystal lattice containing only \\(\\text{Fe}^{2+}\\), \\(\\text{Fe}^{3+}\\), and \\(\\text{O}^{2-}\\) ions. Assuming the crystal lattice is electrically neutral, what fraction of the total iron cations in the sample are \\(\\text{Fe}^{3+}\\)?"
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url: "https://nerd-notes.com/ubq/120185/"
date_modified: "2026-08-21T16:02:52+00:00"
---

# A sample of a non-stoichiometric iron oxide compound has the empirical formula \(\text{Fe}_{0.80}\text{O}\). The solid consists of a crystal lattice containing only \(\text{Fe}^{2+}\), \(\text{Fe}^{3+}\), and \(\text{O}^{2-}\) ions. Assuming the crystal lattice is electrically neutral, what fraction of the total iron cations in the sample are \(\text{Fe}^{3+}\)?

A sample of a non-stoichiometric iron oxide compound has the empirical formula \(\text{Fe}_{0.80}\text{O}\). The solid consists of a crystal lattice containing only \(\text{Fe}^{2+}\), \(\text{Fe}^{3+}\), and \(\text{O}^{2-}\) ions. Assuming the crystal lattice is electrically neutral, what fraction of the total iron cations in the sample are \(\text{Fe}^{3+}\)?

- **A.** \(0.20\)
- **B.** \(0.25\)
- **C.** \(0.40\)
- **D.** \(0.50\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/120185/*