---
title: "A sealed, rigid \\(2.0\\text{ L}\\) reaction vessel holds an equilibrium mixture of \\(\\text{CO(g)}\\), \\(\\text{Cl}_2\\text{(g)}\\), and \\(\\text{COCl}_2\\text{(g)}\\) at \\(350\\text{ K}\\), as represented by the balanced equation below.  \\[ \\text{CO(g)} + \\text{Cl}_2\\text{(g)} \\rightleftharpoons \\text{COCl}_2\\text{(g)} \\]  An additional \\(0.10\\text{ mol}\\) of \\(\\text{Cl}_2\\text{(g)}\\) is injected into the container at constant temperature. Which of the following correctly predicts how the system responds to re-establish equilibrium and the resulting effect on the concentration of \\(\\text{CO(g)}\\)?"
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url: "https://nerd-notes.com/ubq/120284/"
date_modified: "2026-08-23T04:04:16+00:00"
---

# A sealed, rigid \(2.0\text{ L}\) reaction vessel holds an equilibrium mixture of \(\text{CO(g)}\), \(\text{Cl}_2\text{(g)}\), and \(\text{COCl}_2\text{(g)}\) at \(350\text{ K}\), as represented by the balanced equation below.

\[ \text{CO(g)} + \text{Cl}_2\text{(g)} \rightleftharpoons \text{COCl}_2\text{(g)} \]

An additional \(0.10\text{ mol}\) of \(\text{Cl}_2\text{(g)}\) is injected into the container at constant temperature. Which of the following correctly predicts how the system responds to re-establish equilibrium and the resulting effect on the concentration of \(\text{CO(g)}\)?

A sealed, rigid \(2.0\text{ L}\) reaction vessel holds an equilibrium mixture of \(\text{CO(g)}\), \(\text{Cl}_2\text{(g)}\), and \(\text{COCl}_2\text{(g)}\) at \(350\text{ K}\), as represented by the balanced equation below.

\[ \text{CO(g)} + \text{Cl}_2\text{(g)} \rightleftharpoons \text{COCl}_2\text{(g)} \]

An additional \(0.10\text{ mol}\) of \(\text{Cl}_2\text{(g)}\) is injected into the container at constant temperature. Which of the following correctly predicts how the system responds to re-establish equilibrium and the resulting effect on the concentration of \(\text{CO(g)}\)?

- **A.** The system shifts toward the reactants because \(Q < K_c\), which causes \([\text{CO}]\) to increase.
- **B.** The system shifts toward the products because \(Q < K_c\), which causes \([\text{CO}]\) to decrease.
- **C.** The system shifts toward the products because \(Q > K_c\), which causes \([\text{CO}]\) to decrease.
- **D.** The system shifts toward the reactants because \(Q > K_c\), which causes \([\text{CO}]\) to increase.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/120284/*