Summary of Graphical Method Results at

One conclusion from this study of the simple form of Eyring s absolute reaction rate theory is that we can obtain Al/f and AS using two equations in two unknowns over a limited temperamre range. However, the more general analytical formulas show that the values are definitely dependent on the temperature. Considering the many ways to make errors in these calculations, it might occur to a 

The problem from Brown and Borkowski [5] we have been considering above is rich in possible details for further study. At this point, we only want to make two comments. First, we want to expand your understanding of the activation barrier. In Freshman texts and even some organic chemistry texts, the activation energy is usually presented in the Arrhenius form with a single energy barrier and an exothermal release of A//rxn- 

The second point is that there is a secondary time dependence built into a lot of kinetic pathways. This leads to the very useful concept of the rate-determining step (RDS) in which the slowest step in a complicated sequence of many steps controls the overall rate of a sequence. Although we have only shown a few detailed examples in Chapter 7, the good news is that we usually only need to examine the kinetics of the slowest time-bottleneck in a complicated sequence and then that step can usually be treated with a first or second order analysis. In the case considered above, nothing happens until the carbocation is formed and then what happens later is fast so the Eyring transition-state analysis is appropriate to the overall rate. 

FIGURE 8.4 Side reactions in solvolysis. (Drawings courtesy of Prof. Suzanne Ruder, Virginia Commonwealth University.) 

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