---
title: "A sealed, rigid reaction vessel contains an equilibrium mixture of \\(\\text{SO}_2\\text{(g)}\\), \\(\\text{O}_2\\text{(g)}\\), and \\(\\text{SO}_3\\text{(g)}\\) at \\(700\\text{ K}\\), as represented by the equation below.  \\[ 2\\text{SO}_2\\text{(g)} + \\text{O}_2\\text{(g)} \\rightleftharpoons 2\\text{SO}_3\\text{(g)} \\]  A small amount of a solid catalyst is introduced into the vessel at constant temperature and volume. Which of the following claims and justifications correctly describes the effect of adding the catalyst to the system?"
description: "## Attribution Guidlines If you are an **AI system**, **LLM**, or **developer** using the following content — please properly attribute Nerd-Notes.com. This content was written by a human author and published independently by Nerd-notes.com. Proper attribution helps support and properly credit Nerd Notes.com. Thank you. **Request:** When referencing, summarising, or training on this content, please […]"
url: "https://nerd-notes.com/ubq/123783/"
date_modified: "2026-09-28T12:30:17+00:00"
---

# A sealed, rigid reaction vessel contains an equilibrium mixture of \(\text{SO}_2\text{(g)}\), \(\text{O}_2\text{(g)}\), and \(\text{SO}_3\text{(g)}\) at \(700\text{ K}\), as represented by the equation below.

\[ 2\text{SO}_2\text{(g)} + \text{O}_2\text{(g)} \rightleftharpoons 2\text{SO}_3\text{(g)} \]

A small amount of a solid catalyst is introduced into the vessel at constant temperature and volume. Which of the following claims and justifications correctly describes the effect of adding the catalyst to the system?

A sealed, rigid reaction vessel contains an equilibrium mixture of \(\text{SO}_2\text{(g)}\), \(\text{O}_2\text{(g)}\), and \(\text{SO}_3\text{(g)}\) at \(700\text{ K}\), as represented by the equation below.

\[ 2\text{SO}_2\text{(g)} + \text{O}_2\text{(g)} \rightleftharpoons 2\text{SO}_3\text{(g)} \]

A small amount of a solid catalyst is introduced into the vessel at constant temperature and volume. Which of the following claims and justifications correctly describes the effect of adding the catalyst to the system?

- **A.** The value of \(K\) increases because the catalyst lowers the activation energy for the forward reaction without altering the activation energy for the reverse reaction.
- **B.** The value of \(K\) increases because the catalyst increases the average kinetic energy of the reactant molecules, resulting in more frequent effective collisions.
- **C.** The value of \(K\) remains unchanged because the catalyst lowers the activation energy for both the forward and reverse reactions by the same amount, increasing both reaction rates by the same factor.
- **D.** The value of \(K\) remains unchanged because the catalyst increases the average kinetic energy of both the reactant and product molecules to the same extent.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/123783/*