---
title: "A student heats a \\(0.245\\ \\text{g}\\) sample of \\(\\text{KClO}_3\\text{(s)}\\), with a molar mass of \\(122.5\\ \\text{g/mol}\\), in the presence of a catalyst. The \\(\\text{O}_2\\text{(g)}\\) produced is collected over water according to the reaction  \\[ 2\\text{KClO}_3\\text{(s)}\\rightarrow 2\\text{KCl(s)}+3\\text{O}_2\\text{(g)} \\]  The gas is collected at \\(300\\ \\text{K}\\), when the barometric pressure is \\(0.855\\ \\text{atm}\\) and the vapor pressure of water is \\(0.0350\\ \\text{atm}\\). For gas collected over water, \\(P_{\\text{O}_2}=P_{\\text{barometric}}-P_{\\text{H}_2\\text{O}}\\). Assume the reaction goes to completion and use \\(R=0.0820\\ \\text{L atm mol}^{-1}\\text{K}^{-1}\\). Which of the following is closest to the volume of gas collected?"
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url: "https://nerd-notes.com/ubq/120071/"
date_modified: "2026-08-21T08:41:11+00:00"
---

# A student heats a \(0.245\ \text{g}\) sample of \(\text{KClO}_3\text{(s)}\), with a molar mass of \(122.5\ \text{g/mol}\), in the presence of a catalyst. The \(\text{O}_2\text{(g)}\) produced is collected over water according to the reaction

\[
2\text{KClO}_3\text{(s)}\rightarrow 2\text{KCl(s)}+3\text{O}_2\text{(g)}
\]

The gas is collected at \(300\ \text{K}\), when the barometric pressure is \(0.855\ \text{atm}\) and the vapor pressure of water is \(0.0350\ \text{atm}\). For gas collected over water, \(P_{\text{O}_2}=P_{\text{barometric}}-P_{\text{H}_2\text{O}}\). Assume the reaction goes to completion and use \(R=0.0820\ \text{L atm mol}^{-1}\text{K}^{-1}\). Which of the following is closest to the volume of gas collected?

A student heats a \(0.245\ \text{g}\) sample of \(\text{KClO}_3\text{(s)}\), with a molar mass of \(122.5\ \text{g/mol}\), in the presence of a catalyst. The \(\text{O}_2\text{(g)}\) produced is collected over water according to the reaction

\[
2\text{KClO}_3\text{(s)}\rightarrow 2\text{KCl(s)}+3\text{O}_2\text{(g)}
\]

The gas is collected at \(300\ \text{K}\), when the barometric pressure is \(0.855\ \text{atm}\) and the vapor pressure of water is \(0.0350\ \text{atm}\). For gas collected over water, \(P_{\text{O}_2}=P_{\text{barometric}}-P_{\text{H}_2\text{O}}\). Assume the reaction goes to completion and use \(R=0.0820\ \text{L atm mol}^{-1}\text{K}^{-1}\). Which of the following is closest to the volume of gas collected?

- **A.** \(0.00900\ \text{L}\)
- **B.** \(0.0600\ \text{L}\)
- **C.** \(0.0863\ \text{L}\)
- **D.** \(0.0900\ \text{L}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/120071/*