An objective-type test for organic chemistry - American Chemical Society

For example, when ethylidene dibromide is treated with agueous potassium ... to believe that an essay type test helps the student to organize his bowl...
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An OBJECTIVE-TYPE TEST for ORGANIC CHEMISTRY' H. E. PHIPPS Eastern Illinois State Teachers College, Charleston, Illinois

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HATEVER else may be said about objective tests, and a great deal has been said, it is generally' recognized that they do conserve the teacher's time, are easy to grade, and give some measure of the student's progress. Objective tests have not been used to any extent in organic chemistry, yet this particular branch of the science lends itself to such tests, as this paper will attempt to show. Reaction charts of the tvue used bv Underwood.'.

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* Presented before the Division of Chemical Education at the Ninety-first meeting of the American Chemical Society. Kansas City. April 14, 1936.

C o l b e r t , ~ a ~ s eand r , ~others are made up for one or more organic families, depending upon how comprehensive the test is to be. Numbers are substituted in place of the main product or reactant in each individual reaction as shown in Figure 1. The student is expected to place the correct formula for a given product opposite the same number at the side of the sheet. UNDERWOOD, H. W., "Problems in organic chemistry," McGraw-Hill NPWYO& 1926 2x3 ==. nn~ - - ~Bonk Co.. ..~Tnc.. , ..... Citv. -..,, ..-.,--COLBERT, 1. C., "A shorter course in organic chemistry," The Century Ca.,New Yark City, 1931,352 pp. 'HAUSER. C. R., "Chart illustrating organic-reactions of the aliphatic series." J. CHEW.EDUC., 11, 179 (Mar., 1934).

In this way the grading can be easily accomplished by the use of a key. Since the experimental conditions play such an important part in determining the course of an organic reaction, it is well to insist that the student give those conditions in so far as it is reasonably possible to do so. For example, when ethylidene dibromide is treated with agueous potassium hydroxide solution, glycol is formed; but if an alcoholic potassium hydroxide solution is used, acetylene is the product. This is illustrated by numbers 17 and 18 in Figure 1. Then the student would be expected to answer number 17 by writing aq. KOH and number 18 by alc. KOH in the suitable spaces. The statement of other conditions, such as suitable temperatures, catalysts, etc., could be required at the discretion of the instructor. I t is too much to expect that this kind of test will entirely take the place of the usual type of monthly or final examination. I t is offered solely as a supplement to these tests. The writer is still "old fashioned" enough to believe that an essay type test helps the student to organize his bowledge and thinking by writing out in

some detail the answer to a question. However, since many of these examinations contain questions concerned with the writing of equations, this type of objective test would be useful. I t might also be used alone a t certain intervals of, say, two or three weeks, solely for the purpose of determining how much the student has learned about the organic reactions of the family or families just studied. The argument may be raised that the student does not learn to complete and balance equations by this method of testing. Of course he should learn that during his study and class periods but, after all, most organic reactions are relatively simple to balance when the main product and the reactants are known. The f a d that the test, in common with reaction charts, teaches correlation between various compounds and families offsetsthis weakness, in the author's opinion. Summery.-An objective type test, based on the use of reaction charts, is proposed. I t is useful for determining the student's knowledge of organic reactions at frequent intervals or as a supplement to the usual monthly or final examinations.