What has happened to qualitative analysis: A 1966 ... - ACS Publications

We apologize to authors who thus have had to wait to see their work in ... readers that they use their own ingenuity in similar fashion, we are gratif...
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COLLECTION

Quali+a+iveAnalysis E~mon'sNOTE: The papers following Professor Krohn's article on "What Ifas Happened to Qualtitstive Annalysiq" have been collected over s period of months. Similar collections have . 35, 401 (1958); 36, 379 (1959); 37, 407 appeared in previous August issues [J. C ~ E MEDUC., (1960); 38, 406 (1961); 39, 395 (1962); 40, 413 (1963); 41, 435 (1964); and 42, 436 (1965)l. I t is the Editor's hope that putting the articles together in one issue will prove more xttraet,ive to readers than the more frequently used editorial procedure of scattering items such as these bhrough the pages of several issues. We apologize to authors who thus have had to wait to see their work in print. We oommend to readen' attention the fact that often these represent the solut,ionof problems given to freshman students in qualitative analysis conrses. We hope that publication in these pages e m stimulate just such activity. If readers merely incorporate these ideas into their own l~boratoryinstructions, om battle is only half won. If, beyond that, these idem suggest to the readers that they use their own ingenuity in similar fashion, we are gratified.

( Alberiine Krohn University of Toledo

Toledo, Ohio

I1

What Has Happened ..

to Qualitative Analysis? A 7966 survey

1s "aual" dead? On the contrary. qualitative analysis is showing considerable vitality! Three years ago, Hovey reported on a survey made to determine to what extent new concepts in the teaching of chemistry had affected the content and p'ace in the curriculum of courses in qualitative analysis (1). One of the questions askcd was, "What changes are planncd in your treatment of qualitative analysis in the next three years?" This communication rcports a follow-up survey to determine whether the planned changes had been made and what changes are anticipated for the next five years. Questionnaires were sent to the 458 chemistry departments wh ch had replied to the previous survey. Additional questionnaires werc sent to recent users of the Brief Qualitative Analysis Examination, to departments newly accredited by the ACS, and to some new Community and Junior Colleges, making a total of 500. Completed questionnaires wore returned by 403 (81%) of the 500. Table 1 shows the place of qualitat've analysis in the present program. The trend predicted by the 1963 survey is continuing with an approximate 10% increase in courses including qualitative analysis as a part of general chemistry and a corresponding 10% decrease in the number of separate courses. Few replies indicated that no qualitative analysis was taught, but in about 9% of the institutions, less than six weeks of the general chemistry course was devoted to this subject. Apparent y the separate course continues to bc a favored target in streamlining the crowded undergraduate curriculum. However, the ACS Committee on Professional Training states in their minimum requirements under "inorganic chemistry": "Earlier training in descriptive and synthetic inorganic chemis-

Table 1.

Place of Qualitative Analysis in Chemistry Proarom

-1963No.

%

- 1 9 6 b No. %

Totd number giving qua1 as: Part of general

324 fi3.O 305 73.8 156 28.7 76 18.4 Separate oaune 45 11.3 32 7 . 8 Part of analytical Total number of courses cav543 . . . 413 . . . ered by survey T o t d number of students 110.000 . . . 130.500 . . . reoresented ~on;binationsof courses: Part of general only 252 55.0 267 65.9 Separate course only 90 19.7 43 10.6 Part of analytical only 16 3 . 5 12 3 . 0 Both art of eenerd and a. Partof general and part of mdlyticd Separate coune and part of analytical All three Less than six weeks qua1 or no nual

24

5.2

11

3 2

0.7 0.4

6 3

7

1.5

39

try and methods of separation of ions in aqueous solutions is presupposed" (Z). No specification is made as to the manner by which this "presupposed" training is to be obtained. Proponents of the separate course in qualitative analysis believe that it provides a remarkably appropriate setting for the presentation of chemical principles (5). They have objected to "tucking it away" in some corner of the chemistry curriculum such as the second half of the laboratory of the second semester of the general chemistry course (4). Others have found that qualitative analysis can be correlated effectively with the second semcster of gencral chemistry (5). Many join Swift and Schaeffer Volume 43, Number 8, Augusf 1966

/

419

(6) in their belief that "no more effective method has been found for teaching elementary inorganic chemistry than a coordinated lecture-laboratory course based upon a system of qualitative analysis." They point out that a student must assimilate a formidable mass of information in first year college chemistry and will resent the process or forget many of the facts unless the material is related and classified. They further believe "that the periodic table and a system of qualitative analysis are the two most effective aids for this purpose, and that the effectiveness of each is enhanced by the extent to which there is a correlation between them." However, we are warned not to cover too much material in too short a time, because the misuse of qualitative systems in this way has, in the past, led teachers to donbt the intrinsic pedagogical worth of such courses (7). While no one pretends that the main objective of qualitative analysis is to train analytical chemists, does it have little relevance to modern chemical practice? Consulting analytical laboratories report a real need for qualitative analysis (8). It also seems a bit incongruous for a person with a degree in chemistry to be unable to identify quickly, and without the use of a $10,000 gadget, the contents of a container with the label missing. This easily could be the case with the modern generation of chemists whose courses from high school up have shunned "descriptive" chemistry. As Frank put it, "The age of instrumental analysis and of the technician's report tends to glorify costly equipment and to overlook the value of simple experimentation, keen observation, and unbiased interpretation. A course which purposely reverses this trend can have a wholesome effect upon the beginning chemist, engineer, or physician" (9). The laboratory portion of qualitative analysis can be used to develop a spirit of experimental inquiry and critical evaluation which can be the germ of creative research (6). It can help an alert instructor recognize the student who is intellectually and emotionally suited for research so that such students may receive early encouragement in that direction. Frequently in courses which must serve large numbers of unselected freshman chemistry students, qualitative analysis provides the closest practical approach to introductory research on a mass scale (10). I t was found that schools with large numbers of students usually include qualitative analysis with general chemistry. Separate courses in qualitative analysis rarely had large enrollments. This is partly because they were given more frequently in the smaller institutions and partly because they were offered as special courses for chemistry majors or selected students in larger institutions. The only significant change in the average number of semester hours devoted to thestudy of qualitativeanalysis is a slight decrease in the number of laboratory hours as shown in Table 2. Thls was predicted by the 1963 survey. Some mentioned that this represents the number of laboratory hours scheduled, but that additional time is available for students who needed it. Several persons pointed out that additional classroom time in general chemistry is spent on subjects related to the theory of qualitative analysis, such as ionic equilibria, solubility product, electrolytic solutions, etc. 420 / Journal o f Chemical Education

Table 2.

Average Semester Hours Devoted to Qualitative Analysis

Classroom work: Qua1 in General Classroom work: Seosrete Course Laboratory work: Q U ~ Iin General Laboratory work: Separate Course

18 31 46 66

18 31 42 66

Changes planned for the next five years were requested in the 1966 survey. The results are shown in Table 3. The only marked trends would seem to be further decrease in the amount of laboratory time and a continued tendency to eliminate separate courses in qualitative analysis. Otherwise, the situation seems to be a bit more stable than it was three years ago. Table 3.

Changes Planned in Treatment of Qualitative Analysis -Qua1

-1983-

No. Noohangea planned Inoreaae olaaa time Deorehseclhsstime Increase lab time Decrease lab time Drop from program Add to oroaram

%

in general-1966 NO. %

199 59.4 26 19.1 16 11.7 25 18.3 36 28.4 :i 2.2 5 3.6

187 61.4 35 11.5 27 8.8 14 4.6 87 22.4 8 2.6 R 2.0

-Separate -1963NO. %

eaurs-1966

No.

75 48.7 14 17.7 9 11.3 3 3.7 18 20.2 21 26.5 0

%

42 55.3 6 7.9 4 5.3 1 1.3 6 7.9 17 22.4

0.0

0

0.0

Conclusions

Qualitative analysis as a part of general chemistry is gaining in popularity although 18.4'% of the institutions surveyed give a separate course following general chemistry. Over half of these plan to continue the practice for the next five years. Some opposition to qualitative analysis was voiced, but the majority of experienced teachers feel that a modem, flexible, welltaught treatment of the subject is of considerable value both to chemistry majors and to those majoring in related fields. Acknowledgment

The author wishes to express thanks to Dr. Theodore A. Ashford and thc Examinations Committee for financial support of the survey, Dr. Nelson W. Hovey for information based on his experiences with the 1963 survey, and Mrs. Viola Polson for many unpaid hours of assistance. Literature Cited

(1) HOVEY,N. W., J. CHEM.EDUC.,40,410 (1963). (2) ACS COMMITTEE ON PROFESSIONAL T R A ~ N I N"Minimum G, Standards Used as Criteria in Evalnat,ing Undergraduate Professional Education in Chemistry," 1965, p. 5. (3) &NO, EDWARD J., "Q~~&litative Analysis and Electrolytic Solutions," Harcourt, Brace & World, Inc., New York, 1959, p. vii. (4) FREISER,H., J. CHEM.EDUC.,34, 387 (1957). (51 . . HOVEY.NELSONW.. AND KROHN.ALBERTINE. , "Qualitative Analysis," Sernoll, Inc., Iowa. City, 1966, p. i. WILLIAM P., "Qnalita(6) SWIFT,ERNESTH., AND SCHAEFFER, tive Elemental Amlysis," W. 11. Freeman and Co., San Francisco, 1962, pp. v-ix. (7) SWIFT,ERNESTH., AND SCHAEFFER, WILLIAM P., "Teachers Manusl for Qualitative Elemental Analysis," W. H. Freeman and Co., Ssn Francisco, 1961, p. 3. (8) STRONG, F. C., 111, J. CHEM.EDUC.,34, 400 (1957). (9) FRANK,R. E., J. CHEM.EDUC.,34, 383 (1957). J. E., J. CHEM.EDUC.,43,197 (1966). (10) PACKER,

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