Howard Nechamkin Pratt Institute
The Course Content of General Chemistry
Brooklyn, New York
The way in which the subject matter or course content of general chemistry has groan during the past several years is cause for concern. For the past few decades the common organization of time has allotted three hours of clafsroom and three hours of laboratory work each week during one academic year. This has remained true despite the fact that textbooks used for the course have expanded in the number of pages and ideas they contain in an alarming way. Thus, the 1949 edition of one popular textbook contained about 200,000 words; the 1959 edition contains about 260,000. Even more startling, another very well-known general chemistry textbook contained in the 1938 edition about 195,000 words; the 1960 edition contains over 490,000 words! To determine what college teachers believe is the course content of general chemistry, these teachers were approached directly by the use of a questionnaire. The questionnaire was constructed by listing the items that appeared as index entries in twelve textbooks that are most widely used in college general chemistry courses.' This comprised a six-page single-spaced questionnaire consisting of 230 items or topics. The respondents were asked to rate each item according to the scale given in Table 1.
expected. Of the 195 sent out, 105 were returned carefully completed. Some bore pertinent comments reflecting the way in which the respondents viewed the importance of the survey. Unfortunately it is not possible, since anonym it,^ was preserved, to judge the proportion of the returns which represent the impressions of teachers in the various types of institutions. I t is reasonable to hope that the 105 returns were a representative sample of the list of institutions to which mailing was made. Each item on each questionnaire was then tabulated. An A rating by a respondent gave that item a score of 4; B, 3; C, 2; D, 1; E, 0 on his questionnaire. The score which each item received on all questionnaires was then totaled to give an over-all score. On this basis, the highest possible score for any item would be 420 (that is, it rated A on all 105 questionnaires returned). The values were then scaled proportionally so that the maximum value was 400 and the lowest possible was zero. In this way the score values and their evaluation corresponding to the letter designations in Table 1are given in Table 2. Table 2 Score value
Letter value
Table 1 Scale rating
Meaning
A B C D E
Essential for inclusion in the course Important but do not go into detail Would include when time permits Relatively unimportant, may be safely omitted Unnecessary and should be omitted
This questionnarie was then mailed to the "Director of General Chemistry" in each of 195 colleges together with a covering letter explaining the purpose of the survey. The institutions were selected from a listing in the World Almanac and included representatives of large and small colleges and universities as well as those devoted to liberal arts, engineering, and other professional school^.^ The response to what was considered quite a formidable questionnaire was far beyond that
EDITOR'S NOTE:I t should he stated clearly that no interpretation can he made other than that the information here presented reflects the way general chemistry is being taught. This in no way can he construed to mean that the course should be conducted this way. We are confident, too, that any prospective textbook author who patterns his text closely along the lines suggested in this report may well expect his hook to be out of balance s. decade hence.
Table 3 lists all the items in order of decreasing score. This list of evaluations will reveal some surprises. The purpose here is to present the findings and to leave the interpretation of the information to the reader. There are however, several items that are worth emphasis. For example, only 20 of all of the entries were rated 160 or below-an indication that of the items listed, very few were considered nuimportant. No items were rated a t 80 or below, which would have corresponded to exclusion from the course. Interestingly, all of the items relating to thermodynamics, free energy, and entropy ranked very low on the list; this is in spite of the fact that the more recent textbooks are tending to include more of this type of material. This may reflect either the pioneering efforts
1 The author will supply interested readers with a list of theae books. a The author will supply interested readers with a list of these schools.
Volume 38, Number 5, May 1961
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of the textbook authors or the reluctance of the users to agree with the trend. The questionnaire itself was alphabetically arranged, yet there was consistency in the resultant rating of items that were related topically but were widely separated in the order of their appearance in the listing. Thus, Phase rule rated 150 and Phase diagrams 183, but Eutectics rated higher a t 206. Atomic energy rated 285, the Atom bomb 273, and the Einstein equation of muss-energy equivalence scored 286. Partition scored 197; Extraction 195. Thermochemical equations rated 253 and Hess' law 250, yet Heat of reaction scored 342. Curiously, Quantum numbers were rated 253 while the Pauli exclusion principle was rated lower a t 200, but Atomic structure had the very high rating of 394 while the Origin of spectra scored only 272. This makes one wonder how atomic and molecular structure are actually being taught in the classroom in the light of the way these topics are being treated in the newer textbooks. Composition of air rated 353 and the Atmosphere 352. Apparently, identification tests for anions and for cations were considered of about equal importance scoring, 300 and 304, respectively. Some paradoxes in the ratings may have been due to differing interpretations of the topic title or may imply that some topics are treated qualitatively rather than mathematically. Thus, Hydrolysis of salts was rated 383, but the quantitative aspects of hydrolysis, that
is, Degree of hydrolysis and Hydrolysis constant were rated only 298 and 291, respectively. The Gas laws scored 395, but V a n der Waals' equation only 191. Similarly, Colligative properties was rated 346 while Raoult's law was only 298. The Electromotive series was rated 388 but Oxidation potentials only 322 and the Hydrogen electrode even lower a t 272. Chemical bnding scored 390 but General isomaimn only 268. Also, whereas Ionic equilibrium was rated a t 384, Common ion effect scored only 301. Concentrations of solutions was rated a t 398, yet Acticities of ions was only 214 and Titration was 344. Other interesting disclosures were that whereas Bronsted acids scored 356 and Anhenius' theory 355, Lewis acids scored only 278, and that the highest rated of all topics pertaining to organic chemistry, Classifiestion of organic compounds, received a score of only 295. All of the topics pertaining to organic chemistry rated at an average of about 230. This corresponds to an interpretation implying that the subject matter mould be included in the course only if time permitted. An average of about 10% of the total page space in general chemistry textbooks is devoted to organic chemistry. The sequence of topics that come under the heading of descriptive chemistry in order of decreasing score was as expected, LC., the Chemistry of Oxygen (382), Hydrogen (381), Halogens (376), Nitrogen (374), Sulfur (371), Alkali metals (3691, ctc.
Table 3. A Listing of Questionnaire Items and Their Scores
Gas laws
349 348 348 346 346 344 344 343 342 340 340 337 335 336 332 332 330 330 328 327 326 326 326 326 325 322 322 322 322 320 320 318 314 311 313 312 310 310
Hydration of ions Cetalysis Electrich1 conductivity Collicative nrooerties Iron ehemikry' Complex ions litration Eleotrode patentids Eleat of reactions Ion-electron method Dhlton'e LBW Coulomb'e law Aluminum ohemistry Radioactivity Atomic radli Bronsted theory Phosphorus chemistry , Laxu of m u l t i ~ l eproportmns Eleotronegatirity Halogen oryacids Allotro~y Buffer solutions Inert gases Magnesium chemistry Chthode rays Types of cell? Electron sffintty Hydrogen bond , Oxidation potent~als Alloys Graham'a law Mosoly's work Reaotlon rates I ~ n i r a t i o n~ o t e n t i a l s Galvhmo action X-ra s Air, gaetional distillation Hydrogen peroxide
295 294 294 294 292 292 291 290 290 289 289 288 288 286 288 281s 285 284 280 279 278 275 273 273 272 272 271 268 206 266 265 262 258 268 257 253 263 253 253 262 262 250 249 218 248 247 216 244 242 242 240 234 230 230 229 229 228
256
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Journal o f Chemical Education
Clagsifioations of organics Flame testa Boron chemistry Van der Waala' foroes As, Sb, and Bi ohemistry Metallic conduction Hydrolyeis oonstant Cation analytic separation osmotic pree+re Mercury ehem~stry Lend chemistry Isomerism, orgsnia Chromium chemistry Manganese ohemistry Einstein equation Chain resotione Fusion a n d atomic energy Tin chemistry Mass weotrograph Cobalt a n d nickel chemistry Lewis aoids, definition Activation energy Adsorption Atomio bomb Hydrogen electrode Speotrh origin D i ~ o l e&omentaof molecules Isomerism, general Critical constants Reaction kinetios History of chemistry Numenolsture, organic Cadmium diemistry Mass defect Coordlnatmn theory Humidity La>v of van't Hoff Quantum numbers T h e n n o o h e m i d equation8 Orpanio class reactions O d d chemistry HPSS' law Alums Calorimetry Fractional distillhtian Corrosion Beryllium chemistry Hydrocarbon orackrng Subatomic particle seeelerators C ~ o o k e stubes Photosynthesa Cycles in nature Oil drop experiment Paeking fraction Plhtinum mcthla chemistry Distillation liquid mixtures Flotation
.
227 227 227 226 224 222 222 221 220 218 218 217 217 218 214 214 200 204 203 20'3 201 200 200 197 195 193 191 188 187 184 184 183 183 182 180 176 176 175 166 164 150 149 149 148 144 140 137 135 133 131 125 124 124 124 124 117 116 95
Goldsohmidt Poymers Resonance Carbohydrates Magnetism and structure Radioactive dating constant boiling mixtures Isomorphism Tracer techniques Decomposition potential Photochemistry Proteins Reiiigeran gases , Gerlnsnium ohemlatry Aotivitios of ions Ion exohange resin* Euteotis Cannirrem'a method Detergents
Photoeleotrio effect Rare earths chemistry E w i v d e n t oanduothnce Pauli exelusion ~ r i n o i p l e Partition Extraction a n d partition Stereoohemistry Van der Waala' equation Brhgg's law hlaxwell distribution law Activity coefficient Ant~biotios Dew m i n t Phase diagrams P h o t o z r a ~ h ychemistry Ostwald dilution Lay Biographies of c h e m l t e Electron diffraotlon Cellulose products Mineral names K-electron capture Phase rule Ase of minerals Biochemlatry Lanthanide oontraotion Aoheson Dmoeas O ~ t i e sactivity l Aromaticity Air oonditioning Meaon theory Case hardening Freeenergy Cloud chamber Chemotherapy Ensnliotropy , Thermodynam~os Fajan's rules Rntropy
Dyes
