[The teaching of qualitative analysis in secondary schools:] Discussion

[The teaching of qualitative analysis in secondary schools:] Discussion. James E. Wildish. J. Chem. Educ. , 1929, 6 (3), p 492. DOI: 10.1021/ed006p492...
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DISCUSSION I suppose that i t would go without saying that qualitative analysis is given to teach pupils t o analyze. Whether some is given during the latter part of the high-school course, or the year following, it serves another very important purpose, namely, to drill pupils on the fundamentals of elementary inorganic chemistry. To approve such a course as Mr. Kelsey suggests is to sanction a method, perhaps the best method, of impressing these fundamental facts, and at the same time to teach the students to do simple analyses. In the attempt to make chemistty practical, I am afraid that the fundamentals are not receiving the attention that they should have. I n short, we are "applying" a little too freely without having anything to apply. There are a few fundamental concepts that should stand out and clearly differentiate chemistry from the other courses. It is true that the large percentage of the students are not going on to college, but why should they not have definite, accurate ideas concerning these fundamental concepts, which will better enable them to appreciate chemistry in everyday life and to read more intelligently scientific literature, even in newspapers? The amount of scientific literature for the lay reader is rapidly on the increase. This means that the beginning course should give some chemistry, not something about chemistry. For those continuing with some type of scientific work, these fundamentals, well ground in, will well serve as a foundation for the building of future courses. I see no real reason for differentiating between those who are, and those who are not going on t o

college as far as these fundamentals are concerned. Well-chosen, accurate knowledge, in any field, is the most practical. It really makes little difference just what succeeds this fundamental work. Whatever it is, i t should be used largely to drill into the pupils what they have learned during the early part of their course. In presenting these fundamentals, illustrations from the pupil's environment should be freely used, rather than illustrations far removed from their experiences. If it is desirable to put girls into classes by themselves and give them work on sugars, baking powders and so forth, well and good. If it is desirable to put boys, or boys and girls, into another class and make the work such that it might be called applied or practical chemistry, well and good. My contention is that no matter what the course is called, these fundamentals can be and should he kept in the foreground and applications made of them every time opportunity presents itself. Whether a girl has heated five grams of sugar in a test tube or a boy has precipitated copper with hydrogen sulfide, I think that we should not be satisfied unless they can answer such questions as, how many grams of carbon can be obtained from five grams of sugar? What is the chemical reaction involved? What is the percentage composition of sugar? What is the weight of water given off? What weight of copper sulfide can be obtained from a given weight of copper chloride? What volume of hydrogen sulfide will be required, under given conditions, to precipitate the copper? What is the chemical reaction involved? and so forth. Questions such as these show clearly that you can continually drill on the fundamental ideas regardless of what the pupils are doing in the laboratory. These weight and volume relationships, along with some work on solutions, ionization and so forth, can be emphasized all along the line, and unless they are emphasized, the student has not had chemistry, and in the last analysis, the course is not practical. Certainly one of the best ways of continually reviewing pupils on these fundamental concepts is to give them some work in simple qualitative analysis. This is true even if some of it is given during the latter part of their high-school course. This is better, I think, than giving much of the descriptive matter we are now giving, especially after the pupil has studied two or three typical metals. Even some assigned readings, with discussions, of the spirit and service of chemistry would be preferable to much of this material. I would strongly recommend this. As you reduce a great symphony to the tickling of a cat's intestine with a horse hair, and lose the symphony, so you can reduce chemistry to cold bare facts, equations, and so forth, and not get as much as a glimpse of its spirit, let alone its service to humanity. Mr. Kelsey goes a little further and gives qualitative analysis the half year following the year in high school. If it is well done there is no doubt

that it would reenforce the work done the first year. For the student intending to pursue work of a scientific nature, it would be very valuable, especially if there is much discussion with the fundamentals kept continually in mind. If this is done, as Mr. Kelsey suggests, the course will have served its purpose. I wish to emphasize the "well done" for on this depends the value of this or any other course in qualitative analysis. There are few courses where a pupil can kill more time than in a "cook b o o k course in qualitative analysis. They can acquire habits, which from the standpoint of technic, are actually bad. It would seem best not to try to give the course except in high schools where the instructor is fully competent and the equipment adequate. In general, it is better that students take physics before they take chemistry. This would mean in the ordinary four-year high school that the student would take physics during the junior year and chemistry during the senior year. I t would be hard to follow this sequence unless the physics is pushed back to the sophomore year, which perhaps is not advisable. The value received from this course in qualitative analysis, I believe, would more than offsetthe advantage gained in trying to follow the above sequence. Some are complaining of the overcrowded high-school curriculum. If the teacher has the time and the equipment, this course could be offered as an elective. It should be an elective any way, as it would be undesirable to try to require it of all pupils. Those who have done well in their first year's work and who are going to pursue further work of a scientificnature should take it. Mr. Kelsey leaves nothing to be said concerning the breadth and depth of the work for pupils of high-school age. This, in general, should after all be pretty much of a review of the fundamental principles referred to above. Besides the new material that has to be given concerning the methods of analysis, there is ample room for plenty of drill on nearly all, if not all, of the fundamental principles of elementary inorganic chemistry. His contention for straightforward directions for procedure are to the point. If these are not supplemented by discussions as he suggests, the course is liable to become "cook bookey" regardless of these directions. The type forms, especially, should be kept constantly before the pupil. Most of the reactions involved are metathetical. Such general reactions as neutralization, action of nitric acid on metals and sulfides, examples of ammoniation, action of aqua regia, amphoteric reactions, hydrolysis, oxidation-reduction reactions, and so forth. The pupil should be led to see that while a great many reactions are involved, they after all fall under a comparatively few general types. These may be well brought out

in the discussions as suggested by Mr. Kelsey and I consider them one of the most important phases of the course. There is nothing to add to the discussion of the minimum apparatus and the minimum time to be spent on the work. Unless a high school can meet these conditions, it should not try to give this course. In general, there is little to say in opposition to such a course if given as Mr. Kelsey suggests. His discussion of the work done by the high-school students of St. Louis shows that the work is well done.