Kinetics Toolkit

The CD-ROM program Kinetics Toolkit is an essential part of the main text. It is a graphical plotting application which allows data to be input, manipulated and then plotted. The plotted data can be analysed, for example to obtain the slope of a straight line. All data that are input can be stored in files for future use. Instructions for using the program are on the CD-ROM. Help files are available from the Help menus of the Kinetics Toolkit. 

The Kinetics Toolkit is provided so that you can focus your attention on the underlying principles of the analysis of chemical kinetic data rather than becoming involved in the time-consuming process of manipulating data sets and graph plotting. Full sets of data are provided for most of the examples that are used in the main text and you should, as a matter of course, use the Kinetics Toolkit to follow the analysis that is provided. A number of the Questions, and all of the Exercises, require you to use the Kinetics Toolkit in answering them. 

Ideally you should have direct access to your computer with the Kinetics Toolkit installed when you study Sections 1, 3, 5 and 6. 

As a matter of priority you should try to do Exercise 1.1 in Section 1 as soon as possible since it is designed to introduce you to the use and scope of the Kinetics Toolkit. 

It is still possible to study Sections 3, 5 and 6 if you are away from your computer, but you will need to return to those parts, including Questions and Exercises, that require the use of the Kinetics Toolkit at a later time. 

You may wish to use this summary both to plan your study and also act as a checklist. The most intensive use of the Kinetics Toolkit is in Section 5. 

Do nol miss out Exercise I. I below which, as already indicated, provides you with the opportunity to test your understanding of key ideas relating to rale of change, hi addition it provides you with your first opportunity to use the Kinetics Toolkit on the CD-ROM, It is important that you become familiar witli the use of this software. 

This question uses the Kinetics Toolkit. The experimental data that were used for plotting Figure 3.1, the kinetic reaction profile for Reaction 3.1, is given in Table 3.1. It is presented in a form suitable for direct entry into the graphplotting software, although you should note that the E format must be used for inputting powers of ten. For example, 3.230 x 10-3 is input as 3.230E-3. When you have input your data, you should store it in an appropriately named file.)... 

The information in Table 3.1 is presented in a form suitable for direct entry into the graph plotting software in the Kinetics Toolkit. Often with such data, it is more usual to present it so that powers of ten are incorporated into the column headings. So, for example, the column of data for [C10 ] would have numbers running from 3.230 to 0.863. In this case, what form would the column heading take ... 

A kinetic reaction profile for N2O5 measured at 63.3 °C is shown in Figure 5.2. (If you wish to plot this kinetic reaction profile for yourself using the Kinetics Toolkit, the data are given in Table 5.1.)... 

You may wish to use the Kinetics Toolkit to confirm the values of J at 250 s and 750 s in Table 5.2. (To determine the value of the initial rate of reaction would require more experimental data for the early stages of the reaction than that given in Table 3.2.)... 

Make a preliminary estimate of the slope of the straight line in Figure 5.4a. Then go on to use the Kinetics Toolkit to determine both the slope and the intereept. 

By now you should have become familiar with using the Kinetics Toolkit to work through examples that are used in the text and to tackle both Questions and Exercises. Rather than keep making specific reference to using this software, we shall from now on assume that you will use it as a matter of course. 

Thus a label for a column heading in a table could be KiT. (In this case, the numbers that appear in the corresponding column of data are in a form suitable for clirea entry into the graph-plotting software in the Kinetics Toolkit.) However, it is more conventional to include the power of ten in the label. If we return to the previous equation and multiply both sides by 10, then... 

Table 6.1 summarizes the data for the plots in both Figures 6.1 and 6.3. Columns of data for JT (for direct input into the graph-plotting software of the Kinetics Toolkit) and 10 KJT (for the Arrhenius plot) are both given. 

If the Kinetics Toolkit is used in the analysis of the data in Table 6.1, then fitting to a straight line produces very good results. The computed value of the slope is (-9.814 0.002) X 103 K, so that the activation energy is calculated to be (81.59 0.02) kJ mol-. ... 

To use the Kinetics Toolkit values of/and [NO2] from Table 5.2 are required you may have stored these in a file already. New columns can then be created for In/ and ln([N02]) and these quantities can be plotted against one another. (For completeness an appropriate table of data is given in Table Q.2.) You should find that the computer plot is similar to that in Figure 5.4a. 

The slope of the best straight line that can be drawn through the data points, determined using the Kinetics Toolkit, is slope = 1.04dm mol s ... 

This value is the same as that calculated using the Kinetics Toolkit.)... 

Using the Kinetics Toolkit, we thus find that the constant speed of car A is (17.89 0.03) m s k This result, since it is based on a statistical analysis, represents a more valid assessment of the data for car A than that carried out in part (a). 

Figure E.4 shows a plot of ln(7/mol dm s versus ln([F20]/mol dm ). This should be similar to that obtained using the Kinetics Toolkit. The plot is a reasonable straight line although it appears that there is more scatter in the calculated values of J in the earlier stages of reaction. The slope is 1.99 (very close to 2) with upper and lower limits of 2.24 and 1.74, respectively.

Using the Kinetics Toolkit, the slope and intercept of the straight line are slopes-2.945 x 104 k intercept = 32.39... 

Software, including the Kinetics Toolkit, must be installed onto your computer before you can access the applications. Please run INSTALL.EXE from the CD-ROM. 

The Kinetics Toolkit is accessed directly from the Start Programs The Molecular World menu (Figure C.2). 

Part 1 Chemical Kinetics provides an Introduction to chemical kinetics and the analysis of reaction mechanism. The coverage is wide-ranging from basic, well-established concepts to leading-edge research In femtochemistry. The Kinetics Toolkit on the CD-ROM Is a graph-plotting application that Is specifically designed for the manipulation and analysis of kinetic data and Its use Is built Into many of the examples, questions and exercises that appear in the text. 

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