Correction for the kinetics in capillary tube experiment - Journal of

Correction for the kinetics in capillary tube experiment. C. W. Haigh, and H. D. Gesser. J. Chem. Educ. , 1968, 45 (10), p 685. DOI: 10.1021/ed045p685...
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Correction for the Kinetics in Capillary Tube Experiment

College-Industry Cooperation

To the Editor:

To the Editor:

An experiment was described [GESSER, H. D., LITHOWN, CAROLINE, BRA'ITSTON, D., AND THOMPSON, IAN,J. CHEM.EDUC.,44, 387 (1967)l in which the kinetics of thermal decomposition of benzene diazonium chloride were determined, using a capillary tube. The rate was assumed to be proportional to the rate of change in the partial pressure of nitrogen formed in the reaction. This is valid only at constant volume; and since the reaction occurs at constant pressure a small and variable error is introduced. Now

A successful attempt to reduce the tension at the iuterface between industry and academy was made by seven employers and Mercyhurst College, Erie, Pennsylvania, during a three-week period of student internship in December, 1967. Curriculum space for "something different" became available when Mercyhurst College adopted a threeterm plus Intersession calendar beginning in September, 1967. The Intersession, a three-week period between Thanksgiving and Christmas was designed for a single in-depth study, a unique educational experience. Discussion with upperclassmen in the department of natural sciences and mathematics indicated that they would appreciate on-the-job experience to guide them in a choice of careers. This was the catalyst needed to init,iate "internship in industry." Three chemistry majors, five biology majors, and three mathematics majors were assigned singly or in pairs to Americau Sterilizer Company, Data Processing Institute, General Electric Company, Hammermill Paper Company, and Lord ntanufacturing Company in Erie; and to Calgon Corporation, Pittsburgh, Pennsylvania, and American Type Culture Collection in Washington, D. C. In all but one case the student's program had been thoroughly planned by the cooperating institution. In some cases, the student spent the three-week period on one phase of t,he larger research project; and in others, the student was assigned for a few days at a t.ime to different supervisors in order to sample a variety of instrumental techniques. In all cases the students were given plant tours and were briefed on the company's operation. Students kept daily logs to submit to their college instructor and also participated in weekly seminars at the college. Since the internship was a three-credit course, the necessary grade was determined jointly by the company supervisor and a college faculty member. I t is interesting to note that five participants received job offers from the cooperating institutions; three students were strengthened in their desire to pursue advanced degrees. The only feature of the program which has been questioned is the brief time span. The curricular structure does not permit lengthening the period at present. However, as most participants noted, though a true independent research project cannot be completed in three weeks, a thoroughly-planned program can provide a beneficial orientation to the industrial atmosphere. This orientation is what the student,^ and the college are seeking.

d(z/v)/dl

=

k(a - z ) / v

where x is the number of moles of nitrogen formed, n is the initial number of moles of diazonium salt, and u is the volume of solution. And it can be shown that Hence a plot of log ( I , - 1) against t gives a straight line whose slope is -0.4343k. An Arrhenius plot of the re-calculated results is shown in the revised version of Figure 7, which leads to E = 27 kcal/mole; the literature values, also plotted, give 28.5 kcal/mole. This

treatment of the data dispenses with the need (in this experiment) to make "lo" measurements at 0°C.; also, no correction for the vapor pressure of the solvent or chlorobenzene product is required. One of us (H.D.G.) wishes to apologize to P. Borrell and S. C. Nyburg for missing their excellent paper [BORRELL, P., AND NYBURG, S. C., J. CHEM.EDUC.,42,551 (1965)l on a capillary method which is very similar to that developed in his paper.

Volume 45, Number 10, October 1968

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685