Please see images for question. Also attached is the recorded data from the expe

Question

Please see images for question. Also attached is the recorded data from the experiment, which may be necessary to answer the question.

Other information: Upon graphing each column seperately, the graph of Time vs ln absorbance indicates a first order reaction, since it was the only linear graph.

11 Analyze the data graphically to decide if the reaction is zero, first, or second order with respect to crystal violet. graph is the reaction is order, First order: To see if the reaction is first order, it is necessary to plot of the natural logarithm (In A) of absorbance vs. time. Ifthis plot is linear, the reaction is first order. Second Order: To see ifthe reaction is second order, plot a graph of the reciprocal of absorbance vs. time. Ifthis plot is linear, the reaction is second order. Time (Minutes) A 1/A In A 3.0 4.0 2,793 5S8 5.0 3, ISB 6.0 7.0 I 40S 4.2,29 asl 8.0 09 9.0 -1.242 175 10.0 I. Go4 49 11.0 a 040 130 12.0 12 2.189 8.9 29 13.0 2.243 0.419 14.0 12.048 15.0 16.0 0.813 17.0 OS 2. a. 18.0 04 S 22.222 19.0 20.0 032. 3.442 31.2 S

Explanation / Answer

Ans. As you have already deduced that the absorbance vs time graph gives a linear graph that further indicates the reaction to follow first order kinetics with respect to crystal violet.

Now,

Reaction:        CV + Na+ + OH- --------> (CV*-OH) - reaction 1

            Where, CV = crystal violet as reactant ; (CV*-OH) = product

Generalized rate law equation for the above reaction is given by-

            Rate, r = k [CV]x [OH-]y           - equation 1

The above expression (equation 1) indicates that the rate of reaction is ‘x-th’ and “y-th” order with respect to CV and OH- respectively.

Again, it’s evident that-

I. the reaction is first order with respect to CV, and

II. the rate kinetics with respect to OH- is to be ignored.

Thus, rewriting the expression following above two points (I, and II) gives-

            r = k [CV]1 = k [CV]                           ; [OH-] ignored

Thus the rate law expression in terms of [CV] is – “ r = k [CV]”. It indicates that the rate of reaction is directly proportional to [CV] or follows 1st order kinetics with respect to [CV].

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