---
title: "A student seals a sample of \\(1.00 \\, \\text{mol}\\) of \\(\\text{CO}_2(g)\\) in a rigid \\(1.00 \\, \\text{L}\\) container. At \\(250 \\, \\text{K}\\), the student measures the pressure and determines that the ratio of measured pressure to ideal pressure, \\(P_{\\text{measured}} / P_{\\text{ideal}}\\), is less than \\(1\\). The student then heats the sealed container to \\(1200 \\, \\text{K}\\). Which of the following best predicts the value of the ratio \\(P_{\\text{measured}} / P_{\\text{ideal}}\\) at \\(1200 \\, \\text{K}\\) and provides the correct physical justification?"
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url: "https://nerd-notes.com/ubq/119544/"
date_modified: "2026-08-21T06:23:10+00:00"
---

# A student seals a sample of \(1.00 \, \text{mol}\) of \(\text{CO}_2(g)\) in a rigid \(1.00 \, \text{L}\) container. At \(250 \, \text{K}\), the student measures the pressure and determines that the ratio of measured pressure to ideal pressure, \(P_{\text{measured}} / P_{\text{ideal}}\), is less than \(1\). The student then heats the sealed container to \(1200 \, \text{K}\). Which of the following best predicts the value of the ratio \(P_{\text{measured}} / P_{\text{ideal}}\) at \(1200 \, \text{K}\) and provides the correct physical justification?

A student seals a sample of \(1.00 \, \text{mol}\) of \(\text{CO}_2(g)\) in a rigid \(1.00 \, \text{L}\) container. At \(250 \, \text{K}\), the student measures the pressure and determines that the ratio of measured pressure to ideal pressure, \(P_{\text{measured}} / P_{\text{ideal}}\), is less than \(1\). The student then heats the sealed container to \(1200 \, \text{K}\). Which of the following best predicts the value of the ratio \(P_{\text{measured}} / P_{\text{ideal}}\) at \(1200 \, \text{K}\) and provides the correct physical justification?

- **A.** The ratio increases to a value greater than \(1\), because the higher average kinetic energy overcomes intermolecular attractions, making the effect of the non-zero volume of the gas particles dominant.
- **B.** The ratio increases to a value greater than \(1\), because the individual \(\text{CO}_2\) molecules expand in volume when heated, further reducing the empty space available for particle motion.
- **C.** The ratio remains less than \(1\), because the increased collision frequency at higher temperatures causes intermolecular attractions between \(\text{CO}_2\) molecules to strengthen.
- **D.** The ratio increases to exactly \(1\), because at high temperatures both intermolecular attractions and the volume occupied by individual gas particles become completely zero.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119544/*