Kinetic Data Handling

It is obvious that to quantify the rate expression, the magnitude of the rate constant k needs to be determined. Proper assignment of the reaction order and accurate determination of the rate constant is important when reaction mechanisms are to be deduced from the kinetic data. The integrated form of the reaction equation is easier to use in handling kinetic data. The integrated kinetic relationships commonly used for zero-, first-, and second-order reactions are summarized in Table 4. [The reader is advised that basic kinetic... 

Based on the DSC, ARC, and especially the Dewar test data, it is concluded that the substance can be handled safely in stirred systems with circulating cooling if the temperature of the substance does not exceed 160°C. Based on the kinetic data from the Dewar testing ( a = 117 kj/mol, F(Q)... 

Laboratory studies of the kinetics of purified enzymes are usually conducted with enzyme concentrations of 107 to 10 1(1 M, but within cells enzyme concentrations are probably often in the range 10 6 to 10-5 M,25 which may be higher than the concentrations of the substrates upon which the enzymes act. Be cautious in drawing conclusions about kinetics under such circumstances Methods have been devised for handling kinetic data when the concentration of enzyme is greater than Km, a condition that can lead to intolerably high errors if the usual equations are applied.26 27... 

Instead of obtaining excellent fits to theoretical rate laws by studying reactions in very dilute solutions (10 2 to 10 r> M), reactions could be monitored at the same concentrations as those used for syntheses (e.g. > 1 M ). Although this is far from ideal because the reaction medium changes as the reaction occurs, the important point is that relatively few changes in the procedure (requiring little extra effort) are required. Methods of handling the raw kinetic data are considered in Chapter 3. 

For reactor design calculations it is necessary to know the total devolatilization rate as well as the species production rates. Therefore, one needs to include in the reactor model all the reaction rates that are available for the devolatilization of the particular coal. Kayihan and Reklaitis (8) show that the kinetic data provided by Howard, et al. (5,6) can be easily incorporated in the design calculations for fluidized beds where the coal residence times are long. However, if the residence time of pulverized coal in the reactor is short as it is in entrained bed reactors, then the handling of ordinary differential equations arising from the reaction kinetics require excessive machine computation time. This is due to the stiffness of the differential equations. It is found that the model equations cannot be solved... 

The time constant of the detection is the combined effect of the detector ( detector time constant ) and the data handling or recorder system. The time constant of the detector may be partly due to the fundamental kinetics of the detection (e.g. in polarographic detection), but is usually determined by the amplifier and other electronic components. 

The chapter begins with a short introduction to the appropriate mathematical handling of multiwavelength absorption data sets. We demonstrate how matrix notation can be used very efficiently to describe the data sets acquired in such investigations. Subsequently, we discuss in detail the two core aspects of the model-based fitting of kinetic data ... 

The manner in which kinetic data are treated in arriving at an electrode mechanism depends primarily upon whether the technique gives a direct measure of the response of the intermediate or an indirect measure, usually the effect of the chemical reaction on the electrode response of the substrate. In the former case, the conventional way of handling the data is to compare the experimental response with theoretical data in the form of a working curve and determine the mechanism from the best fit with theoretical data. The latter case usually involves the calculation of the electrode response to a particular mechanism and then comparing some measurable quantity, for example the sweep rate dependence of the peak potential, with the theoretical value. Which type of analysis is appropriate, direct or indirect, depends upon the... 

E.W. Chlapowski, H.A. Mottola, Some comparative studies on data handling in variable-time kinetic determinations. Modification of manganese(II) catalysis with 1,10-phenanthroline and some analogs, Anal. Chim. Acta 76 (1975) 319. 

Fig. 2. Representation of a data handling system for measurements in electrode kinetics. References p. 497...

The most important point is that in the TS mode of operation there is no need to wait for a reaction to reach isothermal steady state. This is a large part of the reason why, using TS methods, kinetic data can be collected so much foster than in the conventional isothermal steady state mode of operation. We must also resign ourselves to the feet that TSR methods often yield primary data that cannot be interpreted by conventional methods of data handling. This is disconcerting, and therefore the question that needs to be examined first is how are valid reaction rates to be calculated from the plentitude of seemingly uninterpretable TS data ... 

Experimentally, it would be observed that the reaction rate would be proportional to both [A] and [B]. Kinetic data are normally handled using the integrated forms of the differential equations. The integrated rate equations for very common rate laws such as simple first-order and second-order reactions are well known ... 

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