---
title: "A rigid, sealed container contains an equilibrium mixture of  \\(\\text{NO}_2(g)\\) and \\(\\text{N}_2	ext{O}_4(g)\\) at temperature \\(T_1\\), as shown in the diagram.  \\[ 2\\,\\text{NO}_2(g) \\rightleftharpoons \\text{N}_2\\text{O}_4(g) \\quad \\Delta H^\\circ = -57.2\\text{ kJ/mol}_{\\text{rxn}} \\]  The temperature of the container is lowered from \\(T_1\\) to \\(T_2\\), and the system is allowed to establish a new equilibrium. Which of the following particulate diagrams best represents the mixture at \\(T_2\\)?"
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url: "https://nerd-notes.com/ubq/123893/"
date_modified: "2026-09-28T12:30:57+00:00"
---

# A rigid, sealed container contains an equilibrium mixture of 
\(\text{NO}_2(g)\) and \(\text{N}_2	ext{O}_4(g)\) at temperature \(T_1\), as shown in the diagram.

\[ 2\,\text{NO}_2(g) \rightleftharpoons \text{N}_2\text{O}_4(g) \quad \Delta H^\circ = -57.2\text{ kJ/mol}_{\text{rxn}} \]

The temperature of the container is lowered from \(T_1\) to \(T_2\), and the system is allowed to establish a new equilibrium. Which of the following particulate diagrams best represents the mixture at \(T_2\)?

A rigid, sealed container contains an equilibrium mixture of 
\(\text{NO}_2(g)\) and \(\text{N}_2	ext{O}_4(g)\) at temperature \(T_1\), as shown in the diagram.

\[ 2\,\text{NO}_2(g) \rightleftharpoons \text{N}_2\text{O}_4(g) \quad \Delta H^\circ = -57.2\text{ kJ/mol}_{\text{rxn}} \]

The temperature of the container is lowered from \(T_1\) to \(T_2\), and the system is allowed to establish a new equilibrium. Which of the following particulate diagrams best represents the mixture at \(T_2\)?

![A square box representing a rigid container. In the upper right corner, a legend indicates: filled black circle = N atom; open white circle = O atom. Inside the box, there are exactly 6 NO2 molecules and exactly 1 N2O4 molecule, uniformly distributed. Each NO2 molecule consists of 1 central filled black circle bonded to 2 open white circles in a bent configuration. The single N2O4 molecule consists of 2 bonded central filled black circles, with each black circle also bonded to 2 open white circles. In total, the box contains exactly 8 filled black circles and exactly 16 open white circles. No other particles, labels, text, or annotations appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1790598655-6r930m.jpg)

- **A.** Diagram A
- **B.** Diagram B
- **C.** Diagram C
- **D.** Diagram D

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/123893/*