Agreement, Complement, and Disagreement to “Why Are Some Reactions Slower at Higher Temperatures?”

Document Type

Article

Department or Administrative Unit

Chemistry

Publication Date

5-30-2017

Abstract

In the article “Why Are Some Reactions Slower at Higher Temperatures?” published in this Journal, Revell and Williamson explained, from the enthalpic and entropic aspects, why an A + B → P reaction may proceed more slowly at higher temperatures via an A + B ↔ C → P mechanism using the pre-equilibrium approximation. Their explanation is convincing but may be too abstract for undergraduate physical chemistry students to understand fully. In this communication, a numerical implementation and graphical demonstrations of their explanation are provided for students to use to “see” for themselves a negative activation energy. Although Revell and Williamson perfectly explained the negative temperature dependence of the A + B ↔ C → P reaction rate, great caution must be exercised when their explanation is applied to interstellar chemistry where the pre-equilibrium approximation may be invalid and statistical thermodynamics functions may be ill-defined.

Comments

This article was originally published in Journal of Chemical Education. The full-text article from the publisher can be found here.

Due to copyright restrictions, this article is not available for free download from ScholarWorks @ CWU.

Journal

Journal of Chemical Education

Rights

Copyright © 2017 The American Chemical Society and Division of Chemical Education, Inc.

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