|
|
| Home > JCE Print > Journal of Chemical Education > Issues >
1998
>
September
> |
|
Research: Science and Education
|
|
|
|
The Quasi-Steady-State Approximation: Numerical Validation
|
Richard A. B. Bond, Bice S. Martincigh, Janusz R. Mika
University of Natal, Durban 4041, Republic of South Africa
Reuben H. Simoyi
West Virginia University, Morgantown, WV 26506-6045
|
|
September 1998
Vol. 75 No. 9
p. 1158
|
|
|
|
|
|
|
| Abstract |
|
The quasi-steady-state approximation (QSSA) of chemical kinetics is a mathematical way of simplifying the differential equations describing some chemical kinetic systems. Originally devised by biochemists on an ad hoc basis, it is now recognized as belonging to singular perturbation theory. Ideally, this theory provides an error estimate for the QSSA, but it is too complicated for general use. Various investigations of special cases, invoking exact solutions, give some indications of the applicability of the QSSA. But further clarification is called for, especially since the QSSA is virtually unavoidable in introductory texts on chemical kinetics, while at the same time it is open to misuse in practice. In this note, we explore first the graphical representation of exact numerical solutions of partially nondimensionalized forms of the kinetic equations of some small systems of pedagogic interest, and thereby show that the QSSA is more widely applicable than is often assumed.
Secondly, qualitative discussions of singular perturbation theory and of numerical stiffness are shown to lead to a simple computational test of QSSA validity, which works with intricate and large systems. This procedure is illustrated for the case of the Oregonator.
|
|
| More Information |
 Citation |
Bond, Richard A. B.; Martincigh, Bice S.; Mika , Janusz R.; Simoyi, Reuben H. J. Chem. Educ. 1998 75 1158.
|
Keywords |
physical chem, computational chem, computer assisted instruction, kinetics, mechanisms, equilibrium
|
History |
Created:
Last Updated: |
June 21, 1999
June 24, 2005
|
|
|
|
|
|
| Home > JCE Print > Journal of Chemical Education > Issues >
1998
>
September
> Page
1158
|
|
|
| JCE HS CLIC |
|
Our Secondary School editors work hard to distill all the JCE materials to produce a fraction of particular interest to high school teachers. We call it CLIC.
|
| Contributions Welcome |
| JCE welcomes your submission |
| Advertisers |
| In recent years we have worked hard to better match our advertisers with our readers. When shopping for chemistry education materials, visit our advertisers' WWW sites first. |
| Be An Ambassador |
| Take JCE along on your outreach missions. Copies of the Journal, guest access to JCE Online, our publications catalog, and more are available for your participants. |
|
