would be effective in giving students more exposure to the topic. Frank W. Darrow nhaca College nhaca. NY 14850
identification is straightforward, and if the student should answer incorrectly twice then the program gives the correct answer. The third module examines supersaturation. The student selects a compound with known solubility at a high temperature, adds compound to solvent to make a nearly saturated solution. and then lowers the temperature (the temperature can he lowered, but not raised, at any time-a frustration if you are not prepared for it). Addition of one more portion of solute causes precipitation of solute and an adjustment of the date display to reflect saturation at the lower temperature. The Study Guide's discussion of supersaturation is brief, and the implications of this module need considerable instructor eaolanatian. The final module is a simulation of mixing one of four liquids, ethylene glycol, carbon tetrachloride, gasoline, or alcohol, with an equivalent portion of water. The graphic illustrates the mixture during a ~ h o r ttime after theinitial mixingand then thestudent is a s k ~ dto decide whether the luurds are miscible or not. The separation into immiscible layers is quite clear, but the meaning of what happens with the graphic. when the liquids are miscible is unclear. There is something happening on the screen, some changesare ubserved, but therers noseparation. What are those changes? My experience is that alcohol and water immediately mix to form a solution in which I cannot observe any changes. A student commented that she would have had a hard time deciding the proper answer to the miscibility question in this instance if she did not already know the answer. The operation of the program is gwd. No computw experience rs necessary. I was able to hang it up occasimally, but it relrmted without a problem. The prompts are clear and appro&ate. Once data has been entered it cannot be chaneed easilv . (althoueh . it will self.edlt by replacement in some cir. cumstances~end there are trmea when the ability to go hack a single step instead uf several steps would have been useful, but the "experiments" are short enough that repeating them is not particularly frustrating. There are no problems if the directions are followed carefully. If the directions are not followed then the program does allow the student to do some silly things, but so does a genuine experiment. Solubility could easily be used with a class unit on soluhility. I t reinforces and clarifies several solubility concepts. The Study Guide is too simplistic for thorough understanding, but it can be augmented with standard text readines. Instructors will need to explain careiully how students are to proceed and they will need to help interpret results, hut students will qurckly learn how to respond to the computer prompts. Solubility will help in elementary understanding of the soluhility of solids in water, and of some liquids in water, and supersaturation. As stated in the Study Guide, it is not intended to replace experiments, but it
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Journal of Chemical Education
Solubilil~by Richard Hallgren contains four laboratory simulatron modules dealing with verims aspects of solubility. The first module is a simulated experiment to determine the quantity of a known solid that can dissolve in 100 g of water a t various temperatures. The user may choose one of four comnounds. The student adds the compound to water and watches for the point where excess solid begins to accumulate in the bottom of the beaker. Data is collected a t four temperatures and the computer generates a solubility curve graph. The second module asks the user to identify an unknown compound. The simulation and data collection is exactly the same as in the first program. After the computer generates a graph, the student chooses the identity of the compound from tables andlor graphs provided as resource materials. The third program investigates supersaturation. The student selects one of four compounds about which he knows solubility information. He is instructed to selecta high temperature and to add solute to a point just below the maximum solubility. Then he is instructed to lower the temoerature immediately and add one more pellet of the compound. At this point he will observe all the excess solute coming out of soluriun. The purpose of the last program is to establish the miscibility or immiscibility of four liquids (ethylene glycol, carbon tetrachloride, gasoline, and alcohol) with water. Upon selecting the liquid, the student watches to see whether it mixes with water. A Srudy Guide comes with the computer disk.The Study Guide includes an owrvrew of the lessons. a lirt of ohiecrit,es, background material, experimental procedure, worksheets for the students to fill in, solubility tables, solubility curves, and a glossary. The Study Guide was useful, hut I found it beneficial to modify the worksheets so that students would do those Darts of the program that I intended for them todo. Also supcrsaturation was the cmcept with which my students had themwt difficulty,andyet this concept was not mentioned in the hack. ground material nor defined in the glossary. The purpose of a laboratory simulation computer program is to enable students to perform procedures that they ordinarily would not he able to do. Some orocedures are too daneerous. Others take' too much ~~~~~~timeor thechemicalsand equipment are tw, expensive. The major criticism that I have of Solubility is that it simulates laboratory procedures that are relatively easy for the students to perform in the laboratory. The miscibility part of the experiment, for enample, is performed so easily in real Life, that I wonder why anyone would want to use that portion of the program. As for the soluhilities of solids in liquids, the pressing of a computer key to add another pellet of solid became boring after a while. And when copper sulfate was used, I was disappointed that the color of the solution did not turn blue. In the program's favor, these sections would save time and the exoense of the ~
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chemicals. Perhaps a teacher would wish for their studenrs to do one solubility experiment in the laboratory, and then get some experience with some other chemicals via the computer program. In fact the author of the program does recommend that students oerform actual solubilitv ex~erimentsand 'be familiar with solubil~tyt;rmmology bc. iore using the program. Having had some embarrassing experiments with failed demonstrations of supersaturation, I might recommend that the supersaturation segment of the program be used as a clasa demonstration. I do not recommend it for student use because of two major problems in the interpretation of the directions. If a student adds enough solute to saturate the solution, this part of the program will not work. The program seems to revert back to the first simulation where solubility curves were being generated. Another problem arises when the student is asked to lower the temperature. If the student chooses to lower the temperature by more than 10 degrees, again the program will not work. The difficulties in interpreting the directions in this part of the program could be overcome by a knowledgeable teacher who had the foresight to review the program before using it with his class. But because of these difficulties, I recommend that this supersaturation module be used only as ademonstration. An alternative recommendation is that if students are to use this segment of the program themselves, they be given some extra printed sheets with more specific directions. This is how I had my students use the program. With the clarifying information on the printed sheets, none of my students had difficulty in running the program. The author lists six objectives. The Solubility program is designed to help students: 1. Master the terminology used in working w ~ t hsolubility. 2. Understand basic solute1 solvent relationships. 3. Explain the relationship between temperature and solubility. 4. Define and prepare a supersaturated solution. 5. Draw conclusions from the results of solubility experiments. 6. Improve data interpretation and graphing skills. I believe that a student could accomplish the first five objectives by using this program. I question, however, whether this program would be the best way to accomplish those objectives. As for the sixth objective, I don't think that the program will enhance a student's graphing skills. I would prefer to see a student make his own graph rather than to watch the computer generate one. I used this program with my General Chemistry I1 students at Columbia Greene Community College. The program was available in the Learning Center and students were responsible for running the program on their own time and filling out the printed sheets that I distributed to them. Students were required to do one of three computer programs, of which E.M.E. Solubility was one. The other choices were Project Seraphim Lake Study and Project Seraphim BCTC Investigation. They could also elect to do a second or third program for extra credit. Nine of 20 students elected to do the Solubility program. They were required to collect and analyze data on one known solid and one unknown solid, run the supersaturation demonstration on one known solid, and do the simulation miscibil-
ity cest on all four liquids The average time that it took the students to do this was one hour. I was surprised to find out that the students reported no difficulty in running the nromam. I reallv exnected them to have k & m s with thk su&rsaturation segment. I do believe that theonly reason they did not have problems was due to the rlarifymg information that I supplied to them with the printed materials. No knowledge of computers seems to be necessary in order to run this program. Some of my students had never used a computer before, but appreciated this experience as their first exposure. With the help of the printed sheets that I supplied to them, the students did not need assistance to run the program or to understand the directions. I do suggest that the program he modified to have just one menu to access all four modules. As written, the students need to make three different selections in order to get to either the solubility of a known substance segment or the supersaturation segment. One menu and one key press should be sufficient to access any of the segments. The students were asked whether they found the program useful. Eight of the nine students answered affirmatively. One student appreciated the f a d that it covered material similar to that which we were discussing in class. Another liked the fact that it was much ouicker to do the exoeriments by computer than by traditronal laboratory procedures. A thmd dudent eqoyed finding the ~ d e n t ~of t yan unknownsuhmnre 0 t h ers commented that the program clearly showed them how to find the solubility of a substance and that it cleared up for them the distinction between solute and solvent. The student who didn't find the program useful stated that she did not learn anvthine" new from the program. but that she enjoyed usmg 11 Thestudents wereasked what thpy had learned mom the program. T u o students mentioned miscibility and another mentioned the generalization that solubility of a solid increases with increasinp.tempera. ture. Favorable comments from the students included the following: "It helped me in the understanding of solubility." "The computer is much faster than the normal experiment." "I enjoyed the part where I had to figure out the identity of the unknown." "The supenaturation segment was interesting." Negativecomments from thestudents i n cluded the following: "Trying to determine which mixtures were miscible in each other was difficult because the graphics were not clear." "The adding of the solute was slow and monotonous. I t took too long." Overall, I do not recommend this program for college level General Chemistry. I t may be more appropriate in a chemistry course for nonscience majors or in high school chemistry. The material covered in the promam is too small a oart and too simole a bart of the overall eeneral ehemistrv,cirrieulum. I wouldcover the material in less than 15 minutes of a 45-hour course. Also the laboratory experiments are too easy for the student to complete in the actual lahoratory, and I believe that the laboratory experience would be more valuable than the computer simulation. As mentioned earlier, the
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supersaturation demonstration may be useful on the college level, but the directions need to be written more clearly. Jeanne M. Gizara Columbia Greene Community College Box 1000 Hudson, NY 12534
General Chemiotry, Third Edltlon Kenneth W. Whiffen. Kenneth 0.Galley, and Raymond E. Davis. Saunders College Publlsnlng Company: New York. NY. 1988. xxxli 884 pp. Figs. and tables. 20.8 X 26
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This is a beautifully printed book. I t abounds with multicolored photographs, illustrations, and renroductions. The mint is clear, generally spaced, and highly iegihle. The paper is pleasantly glossy. Taken tog ~ t h e rthese , factors make for a Very read. able hook. One of the features of this hook, as has been the case in previous editions, is the abundance of exercises to he found at the end of the chapter. The users will encounter little trouble in making homework assignments. The tent does a thorough job of solving an adequate number of sample problems. The authors have seriously attempted to present up-to-date materials. Thus, recent developments in such areas as superconducting ceramic materials and tunneling microscopy have been included. In this vein, the list of elements includes those having atomic numbers 10P107, which have no stable nuclides. The organization of the hook is traditional. The usual introductory chapter is fallowed by several chapters on stoichiometry and then structure and bonding. The chapter entitled "Molecular Structure and Covalent Bonding Theories" devotes considerable coverage to the VSEPR theory and perhaps leaves the student with the feeling that it has unusual importance. Chapters 15-21, which cover 204 pages, introduce the student to physical chemistry. All basic physicochemical subjects are adequately covered. Each of these chapters solves a represeutative number of numerical problems and iucludes an extensive number of exercises. The last 10 chapters can he classified as "descriptive chemistry". The first of these deals with metallurgy and includes a very brief description of zone refining. Chapter 23 covers the nontransition metals. The halogens and the noble gases are covered in the same chapter. Because of this reviewer's interest in arsenic chemistry, he must object to the statement on page 726, viz., "All ar." Insenic compounds are poisonous deed, arsenic compounds are, relatively speaking, not very toxic and arseuocholine and arsenobetaine are really quite innocuous. I t serves little to perpetuate such myths. Transition metal chemistry is the subject of chapters 28 and 29 which cover 47 pages. The chapter on nuclear chemistry includes the important and honest statement, fusion as a practical energy source lies far in
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the future s t best." Some of us still remember the 1950's, when we were told that a lump of uranium, the size of a baseball, would furnish abundant, cheap and clean energy almost forever. The final two chapters are concerned with organic chemistry. The approach is quite conventional. The first of these chapters is devoted entirely to the hydrocarbons while the second is concerned with the chemistry of functional groups. The volume reflects the philosophy of most current general chemistry texts in that physical chemistry and numerical problem solving receibe the greatest emphasis. Nevertheless, the text is highly recommended. The physical appearance and format are first class, the authors write well and the instructor is assisted by a wide choice of questions and problems for the student. The text will serve to provide a solid and up-todate foundation for more advanced chemical training. RalDh A. Zinaaro " Texas A 8 M University College Stallon, TX 77843 ~
Fundamentals of Chemistry: General, Organic, and Biological Joseph D. Deleo. Scott, Foresman and Company: Glenview. IL, 1988. 793 pp. Figs. and tables. 20.5 X 26 cm. This text is a new entry into the very competitive market of chemistry for the allied health sciences. The standard course for these students includes elements of inarganic ("general"), organic, and biochemistry. The author does admirably well on the latter two areas hut slips badly in the first area. Let us address first the good features of this book. The presentation makes frequent use of excellent examples from the areas of medicine, health, and biology to relate the concepts to the students' future careers. These vignettes add a great deal of interest to the textual material. The use of frequent illustrations, margin notes, chapter summaries, and lists of key terms and concepts should enhance the learning process. The concise treatments of organic and biochemistry occupy approximately 58% of the 793 papers and are organized along the standard formats of functional groups and classes of compounds. The last three chapters on metabolism are especially well done. The quantitative sections include the usual treatments of stoichiometry, equilibria, kinetin, etc. The oxidation-reduction treatment is probably the weakest of these. The author is weak in the realm of descriptive inorganic chemistry. I t is probably desirable that the author was parsimonious as this reviewer has serious objections to some glaring errors. We find an page 119 Hg+ as the ionic species for mercury(I), but curiously Hgz02 appears on p. 153. This oxide is not well characterized and should he omitted. In the area of nitrogen chemistry,
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Volume 66
(Continued on page A46)
Number 1
January 1989
A45
