A Computer Program for Simulation of Any Complex First-Order Chemical Reaction A general computer program, written in Fortan IV, has been developed which uses the Monte Carlo method to simulate the course for any system consistin6 of first-order and pseudo-firstorder chemical reactions. In the case of the following general reaction AeB-C-D,
f I l t
etc.
the non-zero constants and the initial mole fraction concentrations of A, B, C, etc. gre,provided by the investigator. The relative concentrations of the components are calculated as functions of time by the Monte C d o mmhod and plotted on an on-line printer. The program, including the plot subroutine, requires 50K and takes approximately 5 min to execute on an IBM 360, Model 30, computer. By removing the plot subroutine and reducing the sise of the sample array, this program can be readily adapted to smaller computers. This program is ideal for student use with either a, terminal or an on-line printe;. The student is required to supply oqly relative rate constants and initial concentrations, and he can instantly observe reversible, consecutive, and parailel reactions or any combination of these. Results obtained from this program agree within 1%of integrated values. This a e e m e n t can be improved by expanding the size of the sample array; however, the time required for execution increases proportionally. This program also provides a method for evalusting proposed mechanisms of firstorder and pseudo-first-order chemical resetions by camparing empirical data with cdculated values. A proposed mechanism can often be accepted or rejected by visual inspection. In addition, the program can be used as a method for finding relative rate constants for a. complex reaction by comparing the experimental values with the calculated values and changing the relative rate constants with a corrective iteration process. Directions for the use of this program including a listing of the program with sample input data are available from J. J. Manock upon request. The authors would like to exp& appreciation to the WCU Computer Center for assistance with this project and the North Carolina.Academy of Science for financial support.
JOHN J. MANOCK DAVIDL.HOOFER WESTERN CAROLINA UNIVERSITY 28723 CULLOWKEE, NORTRCAROLINA
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Journol of Chemical Education
