Differential Method of Analysis of Data
The differential method of analysis deals directly with the differential rate equationto be tested, evaluating all terms in the equation including the derivativedCildt, and testing the goodness of fit of the equation with experiment.
The procedure is as follows.
1. Plot the CAvs. t data, and then by eye carefully draw a smooth curve torepresent the data. This curve most likely will not pass through all theexperimental points.
2. Determine the slope of this curve at suitably selectedconcentration values.
These slopes dCildt= rAare the rates of reaction at these compositions.
3. Now search for a rate expression to represent this rAvs. CA data, either by:
1-Picking and testing a particular rate form, -rA= kf (CA), see Fig. 17, or
2-Testing an nth-order form -rA= k CAn :by taking logarithms of therate equation (see Fig. 3.18).
Example:
Try to fit an nth-order rate equation to the concentration vs. time for following data.
Solution:The data plotted in Fig. below:
Now carefully draw a smooth curve to represent the data and at CA = 10, 8,6, 5, 3, 2, 1, draw tangents to the curve, and evaluate them (see column 3).
and plot as in Fig. below.
The slope and intercept of the best line gives n and k.
So the rate equation is:
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
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