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Molecular Dynamics of the F+H2 Chemical Reaction
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H. Douglas Kutz, Jonathan H. Copeland, and George T. Mathai
University of Tennessee at Chattanooga, Chattanooga, TN 37403 |
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Note: |
This program is included in the Advanced Chemistry Collection (SP-28).
To Order Advanced Chemistry Collection |
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Potential energy surfaces and reaction dynamics are standard topics in undergraduate physical chemistry courses. Examining chemical reactions in terms of atomic-level collisions is important in general chemistry courses as well. From an educational standpoint, a major consideration in studying atomic-level collisions is the visualization process that is required. It is common to find in chemistry textbooks static, cartoon-like drawings of colliding atoms and molecules. A much more effective representation of atomic-level collisions involves a dynamic animation of events. During the past several years microcomputers have developed significantly in memory and speed. It is now possible to perform simulations of atom-molecule collisions on a microcomputer. The program presented in this work examines collisions between a fluorine atom and a hydrogen molecule. The F+H2 reaction is studied in terms of the potential energy surface and also in terms of the reaction dynamics associated with this reaction. In the software presented in this work the potential energy surface for the collinear F+H2 system is examined. Bond lengths, bond energies, the transition state, the barrier height, and the reaction exothermicity are identified. Both wire-frame models and contour plots are presented. Several F+H2 collinear collisions are presented in the reaction-dynamics portion of the program. Each collision may be viewed as an animation which shows the F atom and the vibrating H2 molecule approaching each other, forming the FHH transition state, and finally yielding H+HF products. The collision may also be viewed as the motion of the system point on the contour plot of the potential energy surface. This viewing mode demonstrates clearly how the course of the collision is determined by the features of the potential energy surface. The program leads the user in investigating how the reagent energy effects the F+H2 collision and on how the product H+HF energy is distributed. The program also allows the user to create new F+H2 collisions.
This program would be useful in a general chemistry class. As a demonstration or tutorial, it could be employed to present a number of the aspects of atomic-level collisions that are covered in general chemistry courses. The program is ideally suited for use in physical chemistry courses. The first portion of the program would be of considerable benefit in helping the user develop an understanding of potential energy surfaces and related concepts. The second portion of the program would provide the user with an excellent introduction to reaction dynamics. The highly visual and dynamic aspects of this program make it an interesting and effective learning resource. Hardware and Software Requirements Molecular Dynamics of the F+H2 Chemical Reaction will run on a Macintosh Plus, SE or SE/30, Classic or Classic II, any Macintosh II, Quadra, or PowerBook. Molecular Dynamics of the F+H2 Chemical Reaction requires System 4.2 and Finder 6.0 or greater. It can be run from an 800K disk drive; a hard disk is not required. Molecular Dynamics of the F+H2 Chemical Reaction is compatible with System 7. |
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Last Updated: July 19, 2001 Created: December 4, 1996 |
Created by: J. L. Holmes Comments to: jceonline@chem.wisc.edu |
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| © 1997 Division of Chemical Education, Inc., American Chemical Society. All rights reserved. | |