---
title: "A student investigates the gas-phase reaction between nitrogen monoxide and ozone:  \\[ \\text{NO(g)} + \\text{O}_3\\text{(g)} \\rightarrow \\text{NO}_2\\text{(g)} + \\text{O}_2\\text{(g)} \\]  When the temperature of the reaction mixture is increased from \\(298\\text{ K}\\) to \\(310\\text{ K}\\) at constant volume, the rate of the reaction increases by more than a factor of \\(2\\), even though the total collision frequency between reactant molecules increases by only about \\(2\\%\\). Which of the following best explains why the reaction rate increases so substantially?"
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url: "https://nerd-notes.com/ubq/121462/"
date_modified: "2026-08-23T05:04:41+00:00"
---

# A student investigates the gas-phase reaction between nitrogen monoxide and ozone:

\[ \text{NO(g)} + \text{O}_3\text{(g)} \rightarrow \text{NO}_2\text{(g)} + \text{O}_2\text{(g)} \]

When the temperature of the reaction mixture is increased from \(298\text{ K}\) to \(310\text{ K}\) at constant volume, the rate of the reaction increases by more than a factor of \(2\), even though the total collision frequency between reactant molecules increases by only about \(2\%\). Which of the following best explains why the reaction rate increases so substantially?

A student investigates the gas-phase reaction between nitrogen monoxide and ozone:

\[ \text{NO(g)} + \text{O}_3\text{(g)} \rightarrow \text{NO}_2\text{(g)} + \text{O}_2\text{(g)} \]

When the temperature of the reaction mixture is increased from \(298\text{ K}\) to \(310\text{ K}\) at constant volume, the rate of the reaction increases by more than a factor of \(2\), even though the total collision frequency between reactant molecules increases by only about \(2\%\). Which of the following best explains why the reaction rate increases so substantially?

- **A.** The reaction rate increases because the additional thermal energy decreases the activation energy (\(E_a\)) of the reaction.
- **B.** The reaction rate increases because a significantly greater fraction of colliding molecules possess kinetic energy greater than or equal to the activation energy (\(E_a\)).
- **C.** The reaction rate increases because the average kinetic energy of the reactant molecules increases to a value greater than the activation energy (\(E_a\)).
- **D.** The reaction rate increases because the higher molecular velocities significantly increase the fraction of collisions that occur with the correct steric orientation.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/121462/*