---
title: "A student analyzes a \\(1.12\\text{ g}\\) specimen of iron ore. The specimen is dissolved in acid, and all the iron in the resulting solution is converted to \\(\\text{Fe}^{2+}\\text{(aq)}\\). After the excess reducing agent is removed, the solution is diluted to \\(250.0\\text{ mL}\\). A \\(25.00\\text{ mL}\\) aliquot requires \\(10.00\\text{ mL}\\) of \\(0.0200\\text{ M}\\) \\(\\text{KMnO}_4\\text{(aq)}\\) to reach the endpoint. The reaction in the acidic solution is represented by the following equation.  \\[ \\text{MnO}_4^{-}\\text{(aq)}+8\\text{H}^{+}\\text{(aq)}+5\\text{Fe}^{2+}\\text{(aq)}\\rightarrow \\text{Mn}^{2+}\\text{(aq)}+4\\text{H}_2\\text{O(l)}+5\\text{Fe}^{3+}\\text{(aq)} \\]  Assume that only \\(\\text{Fe}^{2+}\\text{(aq)}\\) reacts with the permanganate and that the molar mass of iron is \\(56.0\\text{ g/mol}\\). What is the mass percent of iron in the ore specimen?"
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url: "https://nerd-notes.com/ubq/120029/"
date_modified: "2026-08-21T08:40:40+00:00"
---

# A student analyzes a \(1.12\text{ g}\) specimen of iron ore. The specimen is dissolved in acid, and all the iron in the resulting solution is converted to \(\text{Fe}^{2+}\text{(aq)}\). After the excess reducing agent is removed, the solution is diluted to \(250.0\text{ mL}\). A \(25.00\text{ mL}\) aliquot requires \(10.00\text{ mL}\) of \(0.0200\text{ M}\) \(\text{KMnO}_4\text{(aq)}\) to reach the endpoint. The reaction in the acidic solution is represented by the following equation.

\[
\text{MnO}_4^{-}\text{(aq)}+8\text{H}^{+}\text{(aq)}+5\text{Fe}^{2+}\text{(aq)}\rightarrow \text{Mn}^{2+}\text{(aq)}+4\text{H}_2\text{O(l)}+5\text{Fe}^{3+}\text{(aq)}
\]

Assume that only \(\text{Fe}^{2+}\text{(aq)}\) reacts with the permanganate and that the molar mass of iron is \(56.0\text{ g/mol}\). What is the mass percent of iron in the ore specimen?

A student analyzes a \(1.12\text{ g}\) specimen of iron ore. The specimen is dissolved in acid, and all the iron in the resulting solution is converted to \(\text{Fe}^{2+}\text{(aq)}\). After the excess reducing agent is removed, the solution is diluted to \(250.0\text{ mL}\). A \(25.00\text{ mL}\) aliquot requires \(10.00\text{ mL}\) of \(0.0200\text{ M}\) \(\text{KMnO}_4\text{(aq)}\) to reach the endpoint. The reaction in the acidic solution is represented by the following equation.

\[
\text{MnO}_4^{-}\text{(aq)}+8\text{H}^{+}\text{(aq)}+5\text{Fe}^{2+}\text{(aq)}\rightarrow \text{Mn}^{2+}\text{(aq)}+4\text{H}_2\text{O(l)}+5\text{Fe}^{3+}\text{(aq)}
\]

Assume that only \(\text{Fe}^{2+}\text{(aq)}\) reacts with the permanganate and that the molar mass of iron is \(56.0\text{ g/mol}\). What is the mass percent of iron in the ore specimen?

- **A.** \(5.00\%\)
- **B.** \(50.0\%\)
- **C.** \(71.4\%\)
- **D.** \(250\%\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/120029/*