SIMULATED RESEARCH: A BELGIAN EXPERIMENT ROBERT DELHEZ UniversitC de Li&ge,L i k e , Belgium
F O R some time we have been convinced that labora( b ) Source of anions: KBrOa, NaIOa, K2TeOa, tory courses could be made more interesting, and with Na2Se04,K[Sb(OH)s], NalHAs04, NazMoOa, NazW04, the prompting of R. K. Summerbell's paper' we are (NH4)aWsOli. suggesting an educational experiment which we feel The student was told whether the ion he was to does exactly this. identify was to be positive or negative, but no indicaThe normal laboratory of the "Seconde Candidature tion was given as t o the possible nature of the ion. en Sciences Chimiques" consists of inorganic experiments which are a com~lementarvDart of the first-vear STUDENT RESPONSE course (preparative and descripti;echemistry) and good The students were very enthusiastic about the preparation for the third-year course (analytical chemiswhole project and several reports surpassed our most try). Thus these students would be in a good position optimistic expectations. Many went t o other departto benefit from a "simulated research project" which ments for equipment and some even used a Geiger would enliven their course. counter belonging to a UNESCO exhibition. Here The results of our experiment agreed with the conare some valuable excerpts from several reports which clusions reported from Northwestern Univer~ity.~ we feel are representative of the project as a whole. This serves t o demonstrate that this type of course is La+"tified by Miss M. Descamps. . . . With NaOH, the well fitted to any university. It serves the essential pedagogic purpose of initiating students in both the solution gives a white, jelly-like precipitate, very little soluble in an excess. Some days after, the precipitate loses its jelly-like spirit and method of scientific research. appearance and its solubility in acids decreases. . . . The following is a typical "research problem" which WbOo-' identified by R. Ca~penlier.. . . If some drops of the was given to each of our students: solution are allowed to evaporate on a glass plate, it forms trans-
You are about to receive a sample of a pure mineral salt, either in solid or liquid form. Either the positive or the negative ion of this salt will be completely unfamiliar to you, and you artre to establish the analytical character of this unknown ion so tbat you can identify it in solution with others. In addition,,you are to use your general knowledge of chemistry, your initiative, and any means a t your disposal here to h d as many other physic* chemical properties of this ion as possible. The primary object is not to identify the ion but to act as a research chemist in attempting to study the properties of a new substance and to announce its identification to the scientific world. Write your report in this spirit. Do not forget that this unknown ion may be highly tonic or radioactive and consequently take the due precautions. Goad workla
The salts used were the followine ones: (a) Source of cations: L~~SO;CdC12, Ce(SO&, Ce(NOs)a, CedCOa)a, UOdN03)2, Th(NOd+ La(N0a)a.
' SUMMERBELL, R. K., J. CHEM.EDUC.,31,365 (1954).
'SUMMERBELL,ET AL., J. CHEM.EDUC.,32, 475 (1955). 1 ~t is to continue ctplayingthe that the name appears in the top of the excerpts given in the next section.
parent and colorless small crystals, the most ordinary habibits of the habit no. I is which are the following (here is a. figure) . prevailing. The crystals are often striated parallel to the shortest diagonal of the parallelogram. . . . Tb+' idatified by Cl. MomseboG. . . . (Thedeterminationof a multiple of the atomic weight was accomplished by comparing the weight of an oxalate sample, previously obtained by double decomposition, with the weight of the oxide obtained hy its calcination.) We are here in Cd+' idalijkd by Miss M. C. Philippot. presence of a non-chromogenic ion, more electropositive than hydrogen, but less than iron, neither oxidiaing nor reducing, not radioactive, and belonging to the Cu analytical group. . . . This salt is largely stable toward light and heat. It is very soluble in water and other ionizing solvents, and insoluble in the nonionizing ones.
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ACKNOWLEDGMENT
I wish to thank Pr. L. D'Or, the head of our depare ment, for his interest in the experiment and his authorization t o publish this paper, in the spirit of international pedagogic cooperation.
NEW GENERAL CHEMISTRY TEST,PREPARED BY EXAMINATIONS COMMITTEE FORMM,a new test in general chemistry, is being offered for use by the examinations committee of the Division of Chemical Education. Its Drttern follows tbat of ~revioustests. I t consists of -~ wrrlons on iniormarion, npplirarion of principlt,r, wrrl rrluntima 2nd pwhlems. Ordrrs am1 inquiriesshnuld lwnddn~ss4ro 1 ) r . T A. Ashford, St. Louis University, St. I.ouia .I, \lissouri. (Sce ~ I ~ . P H I.IOI.RNAI., S 33, 9 : (l94G) for nn~munrmirnrof the t a w trrt in organic ehrmiitr,~., ~
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