SEPTEMBER, 1955
SIMULATED RESEARCH FOR FRESHMEN R. K. SUMMERBELL, GREGORY LESTINA, L. CARROLL KING, and H. M. NEUMANN Northwestern University, Evanston, Illinois
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essence of physical science is a mode of procedure. A question is asked of nature in the form of an experiment, and the answer to the question is determined by an interpretation of the experimental results. Nothing could be more exciting to the student who has any potentialities as a scientist. The laboratory portion of our courses can and should use this excitement in motivating the student. It seldom does. In many traditional laboratory assignments the student does not perform an experiment, but rather a personalized demonstration. Such activity has some merit in that it gives the student personal contact with the actual chemicals involved, but it is expensive in time and materials, is often inferior in efficiency t o a well performed demonstration by the teacher, and may even degenerate into mere "busy work." Often the brighter and more independent student is disgusted by such an inane procedure and devises methods of circumventing what he regards as unreasonable demands. Sometimes he cheats, and except in the rare cases where he is caught, receives a higher grade for a dishonest report than for an honest one. EVALUATION OF QUALITATIVE ANALYSIS
One successful modification of the older procedures is to introduce unknowns. Since the answer can no longer be determined by reading a textbook, the
student is not encouraged to cheat and is encouraged to make valid observations. Qualitative analysis traditionally introduces a host of unknowns. In many colleges and universities it has been absorbed into the elementary work and has almo'st disappeared from the curriculum as a separate course. I n schools where this transition has occurred, the gain in student interest and morale in the elementary laboratory has usually been pronounced. There is still room for improvement in traditional qualitative analysis. Laboratory note taking in the typical freshman qualitative analysis course tends to be very sketchy, and reports often consist merely of a list of symbok of the elements found. Mediocre students, slavishly following directions, are too often able to achieve satisfactory grades without ever doing any real thinking. At no point is the student forced to make a real choice as to what he should try next. The making of a correct choice as to the next step is not only a lot of fun for the potential chemist, but the ability to do so is probably the principal characteristic of persons who eventually become outstanding as research men. Our typical undergraduate teaching procednres kill ratlfer than nurture this ability. The better and more carefully written thelaboratory manual, the less likely is the student to exercise originality. I n fact, the superior student who might some day be
JOURNAL OF CHEMICAL EDUCATION
an ornament to the chemical profession is likely to abandon it at this stage as a "cook book" subject. THE SIMULATED RESEARCH PROJECT
At Northwestern University we have been conducting an educational experiment designed to correct some of these deficiencies. By substituting anion analysis for the usual descriptive nonmetal chemistry, and omitting desirable but unessential duplication of unknowns, we are able to use several weeks a t the end of the school year for more fruitful and exciting activities on the part of the student. Each student actually undertakes a simulated research problem. He is given a copious sample of a solution of some ion that was not covered in the regular scheme, and is asked to identify the ion, adopt or devise a scheme of analysis for an unknown containing the usual scheme ions plus this one extra ion, and to analyze a couple of rather simple general unknowns which may or may not contain his personal ion. The mechanics of administration are quite simple. As rapidly as the students complete the traditional assignment, they are turned loose with 25 ml. of a solution of an ion and the following directive. RESEARCH PROBLEM I n the laboratory work thus far you have been given rather specific instructions as to procedure. You are now to be given an opportunity to use your initiative fully and to gather for yourself the facts which will enable you to plan and carry out an analysis. You will he given a solution thst contains an element not covered by the analytical ~chemein our text. It may be any one of the following: Li, Cs, Au, Be, In, TI, Th, V, Mo, W, U, Pt, Ce, Te. You are to "play" with this solution in the laboratory for about an afternoon, finding out all that you can about it. One of the first things to do might be t o find out where it would appear in the regular scheme. Does i t form an insoluble hydroxide? Does i t form soluble complex ions with NHn, CN; &0$-;ete.? Is the hydroxide smphoteric? Is the ion a. reducing or an oxidizing agent? Does i t form an insoluble sulfate, oxslate, etc.? Doerr i t give a flame test or a bead test? While you are doing this kind of experiment, keep copious notes. When you have found out a considerable amount of information you ivill want to go ta the library. I n the reserve room you will find "A Comprehensive Treatise on Inorganic and Theoretical Chemistry" by J. W. Mellor. This 15-volume set of hooks describes the chemistry of the possible elements rather completely. Concerning each element there is a very helpful section entitled Reactions of Analytical Interest. Other small reference books which may prove useful are: Latimer and Hildebrand, "Reference Book of Inorganic Chemistry"; Hopkins, "Chemistry of the Less Familiar Elements"; MoAlpine and Soule, "Qualitative Chemical Analysis.'' By comparison of your laboratory results with the reaction behavior described in the reference books you may be able to identify your element, but you will probably wish to return to the laboratory to do a few critical experiments. Remember to take notes both in the laborstory and the library. On the basis of your original experiments in the laboratory and others thst have been suggated by library reading but verified in the laboratory, you should now be able to identify your element and to plan an anslytical soheme for unknowns containing your "new" element in the presence of any or all of the elements in the regular scheme. D o so, and submit a voluminous report including a description of yaur laboratory experiments, a flow sheet of yaur new scheme that provides for your new element.,
and a summary of any pertinent information that you have gleaned from the library. This report is due a t the close of your last laboratory period preceding May 22. I n working out this research problem you are to feel perfectly free to consult other library sources, the members of the teaching staff, or your fellow research workers. Since the members of the staff will have access to information oonoerning the identity of your "new element" they will not make specific reeommendations, but their ideas about general methods of attack may be helpful. Consult them freely, particularly when you have exhausted your own ideas as to possible modes of procedure. Remember, however, that you youmelf have done the experimental work and that you have more direct information about your nrohlem than anvhodv else.
which may contain your new element. Analyze these according to your own new scheme and report the remits. The identification of your unknown element will probably take two weeks, leavine another two weeks for the analysis of the two unknown solutions. You will be graded on initiative, originality, perseverance, independence, and the excellence of your report, as well as on the analysis of the unknowns. I t may happen that in your work you will need a reagent not on the side shelf. A list will be maintained on the bulletin
STUDENT RESPONSE
The students went t o work-with enthusiasm and the instructor experienced one of the most thrilling episodes in his teaching career. Laboratory note taking was no longer a chore that an unreasonable teacher insisted upon, but a perfectly logical and necessary aid in arriving a t an objective. Accurate laboratory observation was of vital interest to the individual student. Differences in reaction for different valence states became something very real. The privilege of extra time in the laboratory xas demanded. Groups of students argued chemistry in the halls, in the laboratory, and in the lecture rooms before and after class. The librarian complained that the students disturbed others by their arguments in the library. The students dug up other (and, of course, much better) reference books. Several of the students who had acquired a reading knowledge of German in high school hunted up classical German treatises and found them extremely helpful. A few even consulted original journal articles and many were impressed with the real necessity of acquiring a reading knovledge of German at the earliest opportunity. All of the students succeeded in identifying their ions, concocting or adapting an analytical scheme, and using the latter to analyze the general unknowns. Incidentally, the results were considerably better on these general unknowns than on those that just preceded the research project. These improved results were partly due to increased experience, hut the writers like to think that they were in part due to better observation and better understanding of the nature of the chemical principles and reactions involved. The h a 1 reports took various forms and were of
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assorted excellence, but they were uniformly better than would be expected from experience in reading examinations and required written work from the same and similar students. The pride in personal accomplishment and the desire to present that accomplishment adequately stood out. EVIDENCE OF RESEARCH PSYCHOLOGY
We have called the project "simulated research" and we believe that that term was fully justified by the results. (The students coined the name "superduper unknown.") Most of the sensations of the active researcher were duplicated by the students. Several tvoical exrerots from the r e ~ o r t swill illustrate this ~ o i n t . [Student working on Ce+'] . . . I got this brown preoipitate a t " A
least three times. The last time I added (NH4)>S,I added it far to excess and got a hlsck eulfide. At this point I was sure I had vanadium. . . . When I started to confirm vanadium, I was in for quite a surprise. [Six tests that were negative for vanadium Having eliminated vanadium rather decisively, I follow.] started again on the idea that i t might he cerium. [Three positive Now that it began to look very much tests for Ce+Vollow.] like C e i 4 .1decided to do the test w-a i n which originalh .. . made me decide against cerium.
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[Student working on uranium] . ..By oompari~onof these tests and my preliminary experiments, I suspected that my unknown element was uranium, and ruled out the other possibilities by the following reasoning. [Here the student recited the results of miscellaneous tests that he had performed in characterizing the ion.] . . A t this point further study on uranium was useless until I- oonfirmed mv sus~ieionbv running several more tests for that element.
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[Student wwking on platinum] . . . At this point I thought that I had gold. I added NH,OH and HCl in a n attempt t a adjust the acidity for HIS precipitation and noticed to my surprise that a yellow precipitate formed. I wondered about this precipitate far s while and then promptly forgot the whole thing. Lster, while reading about some reactions of platinum, I found that N H X l will form a vellow ~ r e e i d t a t ewith HxPtC4. I was then~eonvincedthat-my unknoxtn was platinum.
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. 'My next move was to run a [Student working on TI+] series of tests to prove thallium and to disprove the other ions. I ran a. flame test a n my unknown which gave a green flame for a. very short period of time. Thallium is the only ion which gives insoluble chlorides and also gives a green flame. I was now fairly sure that my unknown contained thallium. . . As further proof of the presence of thallium, I tested the solubility of some of the The chloride was soluble in hot water and the chromate was soluble in both nitric and sulfuric acids. . With AgNOz I should have obtained a white precipitate of TINOr AgNOa, hut did not. . . The number of positive tests for thallium that I got seemed to outweigh the number of tests that failed. I assumed t h a t some did not work because of adverse conditions, such as concentration or temperature.
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[Student working a n Cet3] . . . I became aware of the presence of cerium as my unknown through the interjections of several of my lab asmciates. Prior to their assistance, I had been laboring under the miaepprehension that I was working with uranium. . . . Upon considering the possibilities of cerium, I saw that it was definitely indicated by my previous lab work.
Can any active researcliman read the above excerpts without recalling similar experience and sensations in his day-today work? You could talk to these students about a "tentative working hypothesis" and they
knew what you were talking about. They understood "the scientific method" because they had used it personally. CONCLUSION
The chemistry teacher who habitually gives the traditional course will object vigorously t o the time devoted to such projects. He will say that he has no time now for a great many important subjects that are susceptible to laboratory treatment and that if another 25 hours are subtracted -*? ***** ""'*. There is altoeether too much validity in such objections for comfort. However, a sense of proportion is necessary. At best, about ten per cent of the facts and principlrs contained in the average course can be illustrated in the laboratory. Projects like this one will reduce the eight and per cent. The loss is one and one-half per cent of the total course content. This is a small price to pay for the enthusiasm generated, for the very real of +h ,e specific nature of the qualitative scheme and of general nature of scientific procedure. Best of all, the students are given some small indication of the excitement qf ezper&at
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ACKNOWLEDGMENT
We desire to thank Dean 8. E. LeLand of the Cotlege of ~ i b ~~t~ ~ for ~ furnishing ~ l funds to pay for ad. exditional 'abOrator~assistance during the perimental phases of this project.
