---
title: "A student reacts a sample of pure aluminum metal with an excess of hydrochloric acid according to the following balanced chemical equation:  \\[ 2\\,\\text{Al}(s) + 6\\,\\text{HCl}(aq) \\rightarrow 2\\,\\text{AlCl}_3(aq) + 3\\,\\text{H}_2(g) \\]  The generated \\(\\text{H}_2(g)\\) is collected over water at \\(27^\\circ\\text{C}\\) (\\(300\\text{ K}\\)). The experimental data obtained by the student are recorded in the table below.  | Quantity | Measured Value | |—|—| | Mass of \\(\\text{Al}(s)\\) reacted | \\(0.0540\\text{ g}\\) | | Total barometric pressure | \\(780\\text{ torr}\\) | | Temperature of gas and water | \\(27^\\circ\\text{C}\\) (\\(300\\text{ K}\\)) | | Volume of wet \\(\\text{H}_2(g)\\) collected | \\(59.1\\text{ mL}\\) | | Vapor pressure of water at \\(27^\\circ\\text{C}\\) | \\(20\\text{ torr}\\) |  Given that the molar mass of \\(\\text{Al}\\) is \\(27.0\\text{ g/mol}\\) and \\(R = 0.0821\\text{ L}\\cdot\\text{atm}/(\\text{mol}\\cdot\\text{K})\\), what is the percent yield of \\(\\text{H}_2(g)\\) for the reaction?"
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url: "https://nerd-notes.com/ubq/121519/"
date_modified: "2026-08-23T05:05:00+00:00"
---

# A student reacts a sample of pure aluminum metal with an excess of hydrochloric acid according to the following balanced chemical equation:

\[ 2\,\text{Al}(s) + 6\,\text{HCl}(aq) \rightarrow 2\,\text{AlCl}_3(aq) + 3\,\text{H}_2(g) \]

The generated \(\text{H}_2(g)\) is collected over water at \(27^\circ\text{C}\) (\(300\text{ K}\)). The experimental data obtained by the student are recorded in the table below.

| Quantity | Measured Value |
|—|—|
| Mass of \(\text{Al}(s)\) reacted | \(0.0540\text{ g}\) |
| Total barometric pressure | \(780\text{ torr}\) |
| Temperature of gas and water | \(27^\circ\text{C}\) (\(300\text{ K}\)) |
| Volume of wet \(\text{H}_2(g)\) collected | \(59.1\text{ mL}\) |
| Vapor pressure of water at \(27^\circ\text{C}\) | \(20\text{ torr}\) |

Given that the molar mass of \(\text{Al}\) is \(27.0\text{ g/mol}\) and \(R = 0.0821\text{ L}\cdot\text{atm}/(\text{mol}\cdot\text{K})\), what is the percent yield of \(\text{H}_2(g)\) for the reaction?

A student reacts a sample of pure aluminum metal with an excess of hydrochloric acid according to the following balanced chemical equation:

\[ 2\,\text{Al}(s) + 6\,\text{HCl}(aq) \rightarrow 2\,\text{AlCl}_3(aq) + 3\,\text{H}_2(g) \]

The generated \(\text{H}_2(g)\) is collected over water at \(27^\circ\text{C}\) (\(300\text{ K}\)). The experimental data obtained by the student are recorded in the table below.

| Quantity | Measured Value |
|---|---|
| Mass of \(\text{Al}(s)\) reacted | \(0.0540\text{ g}\) |
| Total barometric pressure | \(780\text{ torr}\) |
| Temperature of gas and water | \(27^\circ\text{C}\) (\(300\text{ K}\)) |
| Volume of wet \(\text{H}_2(g)\) collected | \(59.1\text{ mL}\) |
| Vapor pressure of water at \(27^\circ\text{C}\) | \(20\text{ torr}\) |

Given that the molar mass of \(\text{Al}\) is \(27.0\text{ g/mol}\) and \(R = 0.0821\text{ L}\cdot\text{atm}/(\text{mol}\cdot\text{K})\), what is the percent yield of \(\text{H}_2(g)\) for the reaction?

- **A.** \(40.0\%\)
- **B.** \(53.3\%\)
- **C.** \(66.7\%\)
- **D.** \(80.0\%\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/121519/*