ABSTRACT
In Chapter 7, we tried to form a good foundation for the study of reaction rates using quantitative measurements. The topic of kinetics deserves a full-semester course, and the classic text is Kinetics and Mechanism [1] initially by Frost and Pearson with an updated third edition by Moore and Pearson. Here, we go beyond the straightforward first-or second-order reactions to a few complicated multistep reactions. The main theme of this chapter is the use of the ‘‘steady-state approximation,’’ which is a pencil-and-paper method to treat reactions, which include transient intermediate species in the overall reaction. Today, complex reactions are studied using computer modeling, but the penciland-paper steady-state treatment still has educational value in explaining the principles of transitionstate intermediates (Eyringmodel), chain reactions, and enzyme kinetics. One goal of this chapter is to learn how to treat reactions according to the Eyring transition-state model to report entropy changes as well as energy changes in the transition state. Another goal is to appreciate how complicated chain reactions can be by studying the solvable scheme for the reaction between H2 and Br2. Finally, the important case of enzyme kinetics is treated by deriving the Michaelis-Menten equation with and without a competitive inhibitor. These cases and a few others all depend on some form of the steadystate concept. This admittedly short list of applications was selected as the ‘‘essential’’ topics needed by students in prehealth science, forensic science, and chemistry. Informal interviews of students from this course now in industry or graduate studies have helped form this small list over a number of years. This author always asks graduates of this course, ‘‘Did you use the topics we learned in physical chemistry?’’ and the list of topics has been adjusted several times. Thus, the topics here are the result of that selection process.
