---
title: "A student analyzes the reaction energy profile for the gas-phase reaction  \\(\\text{NO}_2\\text{(g)} + \\text{CO(g)} \\rightarrow \\text{NO(g)} + \\text{CO}_2\\text{(g)}\\), as shown in the graph below. Based on the profile, what are the activation energy (\\(E_a\\)) and the enthalpy change (\\(\\Delta H\\)) for the forward reaction?"
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url: "https://nerd-notes.com/ubq/119233/"
date_modified: "2026-08-19T12:39:29+00:00"
---

# A student analyzes the reaction energy profile for the gas-phase reaction 
\(\text{NO}_2\text{(g)} + \text{CO(g)} \rightarrow \text{NO(g)} + \text{CO}_2\text{(g)}\), as shown in the graph below. Based on the profile, what are the activation energy (\(E_a\)) and the enthalpy change (\(\Delta H\)) for the forward reaction?

A student analyzes the reaction energy profile for the gas-phase reaction 
\(\text{NO}_2\text{(g)} + \text{CO(g)} \rightarrow \text{NO(g)} + \text{CO}_2\text{(g)}\), as shown in the graph below. Based on the profile, what are the activation energy (\(E_a\)) and the enthalpy change (\(\Delta H\)) for the forward reaction?

![A 2D reaction coordinate energy profile plotted on x and y axes in grayscale. The vertical y-axis is labeled Potential Energy (kJ/mol) with horizontal gridlines at intervals of 10 from 0 to 100. Numerical tick marks 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 are displayed along the y-axis. The horizontal x-axis is labeled Reaction Coordinate with no units. A single continuous solid curve begins at a flat horizontal plateau at y = 40 labeled NO2(g) + CO(g), rises smoothly to a single peak maximum at y = 90, and then falls smoothly to a lower flat horizontal plateau at y = 10 labeled NO(g) + CO2(g). Thin dashed horizontal lines extend from y = 10, y = 40, and y = 90 across the plot to highlight energy levels. No other curves, text, or arrows appear on the graph.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/energy-profile-1-1787143169-4QmL1w.jpg)

- **A.** \(E_a = 50 \text{ kJ/mol}\) and \(\Delta H = -30 \text{ kJ/mol}\)
- **B.** \(E_a = 90 \text{ kJ/mol}\) and \(\Delta H = -30 \text{ kJ/mol}\)
- **C.** \(E_a = 50 \text{ kJ/mol}\) and \(\Delta H = +30 \text{ kJ/mol}\)
- **D.** \(E_a = 80 \text{ kJ/mol}\) and \(\Delta H = +30 \text{ kJ/mol}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119233/*