---
title: "A student investigates a high-pressure air-treatment reactor that oxidizes \\(\\text{NO(g)}\\) according to the following proposed mechanism. The first elementary step is a rapid pre-equilibrium.  \\[ 2\\,\\text{NO(g)} \\rightleftharpoons \\text{N}_2\\text{O}_2\\text{(g)} \\]  The second elementary step is slow.  \\[ \\text{N}_2\\text{O}_2\\text{(g)}+\\text{O}_2\\text{(g)}\\rightarrow 2\\,\\text{NO}_2\\text{(g)} \\]  At \\(298\\ \\text{K}\\), the rapid step has \\(K_c=0.20\\ \\text{M}^{-1}\\), and the slow step has \\(k_2=1.0\\times10^3\\ \\text{M}^{-1}\\text{s}^{-1}\\). Immediately after the pre-equilibrium is established, \\([\\text{NO}]=0.050\\ \\text{M}\\) and \\([\\text{O}_2]=0.100\\ \\text{M}\\). What initial rate of formation of \\(\\text{NO}_2\\) is predicted by the mechanism?"
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url: "https://nerd-notes.com/ubq/120078/"
date_modified: "2026-08-21T08:41:15+00:00"
---

# A student investigates a high-pressure air-treatment reactor that oxidizes \(\text{NO(g)}\) according to the following proposed mechanism. The first elementary step is a rapid pre-equilibrium.

\[
2\,\text{NO(g)} \rightleftharpoons \text{N}_2\text{O}_2\text{(g)}
\]

The second elementary step is slow.

\[
\text{N}_2\text{O}_2\text{(g)}+\text{O}_2\text{(g)}\rightarrow 2\,\text{NO}_2\text{(g)}
\]

At \(298\ \text{K}\), the rapid step has \(K_c=0.20\ \text{M}^{-1}\), and the slow step has \(k_2=1.0\times10^3\ \text{M}^{-1}\text{s}^{-1}\). Immediately after the pre-equilibrium is established, \([\text{NO}]=0.050\ \text{M}\) and \([\text{O}_2]=0.100\ \text{M}\). What initial rate of formation of \(\text{NO}_2\) is predicted by the mechanism?

A student investigates a high-pressure air-treatment reactor that oxidizes \(\text{NO(g)}\) according to the following proposed mechanism. The first elementary step is a rapid pre-equilibrium.

\[
2\,\text{NO(g)} \rightleftharpoons \text{N}_2\text{O}_2\text{(g)}
\]

The second elementary step is slow.

\[
\text{N}_2\text{O}_2\text{(g)}+\text{O}_2\text{(g)}\rightarrow 2\,\text{NO}_2\text{(g)}
\]

At \(298\ \text{K}\), the rapid step has \(K_c=0.20\ \text{M}^{-1}\), and the slow step has \(k_2=1.0\times10^3\ \text{M}^{-1}\text{s}^{-1}\). Immediately after the pre-equilibrium is established, \([\text{NO}]=0.050\ \text{M}\) and \([\text{O}_2]=0.100\ \text{M}\). What initial rate of formation of \(\text{NO}_2\) is predicted by the mechanism?

- **A.** \(0.10\ \text{M}\text{s}^{-1}\)
- **B.** \(0.50\ \text{M}\text{s}^{-1}\)
- **C.** \(1.0\ \text{M}\text{s}^{-1}\)
- **D.** \(2.5\ \text{M}\text{s}^{-1}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/120078/*