REVIEWS drill, and part C, the titration simulation and data collection. The combination of the background and booklet is a better presentation than the first two parts of the program. The main advantage of placing this material in the program is to make the program self contained. The first module of the program is mainly text, which is better done in the documentation. The use of the forward and reverse arrows to change pages is an excellent idea and allows the student to move a t his or her own reading pace. This use of the arrow is not continued in part 3, in which the author introduces the five parts of this module. Each part is put on the screen in a time delay, which initially seems like a novel idea. However, at this point the students want to push forward to the actual titration. Part one is entitled A Review of Molarity and Concentration, but the module starts with the ion product of water and the dissociation of acids and bases. Molar concentration is not defined until the sixth page. This definition, which lacks clarity, belongs at the beginning. The example given is one mole of NaF dissolved in one Liter of solution. The molar concentration is therefore 1 M.The author fails to mention the dissociation of solute into Naf and F-. each of which has a concentration of approx&ately 1M. The use of a weak acid, acetic acid, in a concentration of .05 M is a poor choice for the next example. The concentration of acetic acid molecules is given as .05 M with no mention of the partial dissociation of acetic acid. The next part of the module briefly defines pH and the E notation. Then, the module reviews the dissociation of a strong acid and the resulting ion concentrations. Finally, the reviewmodule finishes with an example of neutralization. AU of this can be done as effectively on paper as on the screen. The second module is the lab math drill. The drill starts with a drill on DHfrum different concentrations of H C ~ solutions. There are five randomly generated concentrations ranging from 10W M to lo-" M solutions. The lower concentrations create a serious problem. For example, 10-l4 M HCI solution does not produce a pH of 14. Nor does a 10-8 M HCl solution produce a water solution containing 10-8M H+. Thesolution may contain 10V M C1-, but because of the ionization of water, the [Ht] is greater than 10-8M. Finally, in this module, the program randomly generates different volumes and different concentrations of HBr to be neutralized with different concentrations of NaOH. Each time the program asks the [Ht], pH, moles of H+,moles of OH-needed to neutralize the solution, and volume of NaOH needed for the different coneentrations. Each step gives a yes or no answer and exolanation for each rieht or wrone answer. A I the ~ drill can be and is done onpaper in thestudent booklet. Mast ofthestudentndo the calculations on paper anyway. Or unfor. tunately, the students use the computers for their calculations. The final module is an actual simulated titration using a buret. A colored screen is preferred since the charm of the titration is ~
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Journal Of Chemical Education
to see the indicator change from clear to blue. Before the titration is performed the student must select the right basic reagent from a shelf and make up the right concentration. The program puts the molecular weight upon the screen of the solid chosen. The program will accept a mass with three significant figures. The program tells the student how to make the solution after accepting an answer. Then, the program proreeds to tell the student if the correct reagent waschosenand the right amount measured. If the student is wrong, the program reverts to the beginning of the module, and the student has to start over. At this point, some students cannot figure what is wrong if they rounded their value for the mass incorrectly. Also, same teachers a t the beginning Level emphasize units. The program will not accept 0.146 g. Once the standard solution of base is made, the titration is done. The initial volume of the buret is read. The standard solution is delivered to the solution of unknown acid by one-third of a milliliter per turn of t h e stopcock. When t h e end point is reached, the student must stop the titration student must refill the buon his own. The -~ ret if the end point ia uvershot and redo the titratiun. Finally, a swpwise calculation ia made to get the concentration of the acid. One assumes a one to one mole ratio of acid to base in the calculations. Student reaction to the program varied with the experience of the student. The advanced students felt t h a t the titration should be more varied. Once the experiment was completed, the good students felt they had completely mastered the program giving them little opportunity for variation. The average students felt a certain amount of frustration since they felt that to perform the titration they had to know the material before entering the program. These students felt that the first two modules were of little value because thev eould not Learn the marenal through the program. Hoth groups. thegood and average students, agreed that ~f they had dune the tltratlon in the labora tory, then the program was of little use. Also, both groups agreed that the math drills were good reviews and were helpful in doing a titration calculation. The students felt the program eould be used as a device for a beginner with little experience in titration as an entry. Beyond entry level and review, the program loses its effectiveness. Most students did not like to use the program as review. They did not like to go through the pages or get rntu a part of the program they eould not exit. Most of the students liked the actual titration but were unwilling to get to the titration part a seeond time. Very few of the students could get through all three modules in a fifty-five minute oeriod. -The author should he commended for his effort. However, wrth newer programs, wlth better graphics, or with computer interfacing systems, this program seems outdated. Also, a teacher should try to do experiments or demonstrations as much as possihle in the laboratory. Titrations are not expensive, nor do they require unusual equipment, especially if one substitutes medicine droppers for burets. Thus, the necessity of detailed procedure is removed, one rationale for a titration simulation. Moreover, the hazards are at a minimum when concentrations are held to less than 0.1 M. Thus, ex~
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cept for instructional purposes, a program seems to he a poor substitute for actual titratian. Philip H. Ogata Boulder High School 1604 Arapahw Boulder. CO 80302 Simplex-V: An Interactive Computer Program for Experimental Optlmizatlon S. N. Demlng and S. L. Morgan Statistical Programs, 9941 Rowletl. Suite 6. houston, TX 77075 Hardware: IBM PC Componenlr: 1 disk and manual Level and Subleek Advanced chemical statistics Cost: $150.00.
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Summary Ratlngs:
catww Ease of Use Sub/en hiafter Content PedaQogic Value: S M m t Reaotion:
This disk and documentation package provide a valuable tool for performing the calculations necessary to select new factor levels in optimizing experimental conditions involving simplex methodology. The user needs to be familiar with response surface methodology, experimental design, simolex ootimization.. and fundamental personal computer system operation.r in order to appreciate fully the program. For those not su well versed in these topics the documentation material provides ample help and lists additional references. A tutorial is provided toguide the user through the execution of the program SIMPLEX-V. The program is aimed a t advanced students who have had previous experience with simplex optimization and who might he enrolled in an advanced chemical statistics class. An instrumental analysis class could readily use the program as a tool to carry out an optimization. Students in such a class found the program easy to follow and encountered little difficulty in running the program. Typically, less than 15 minutes were reouired for a student to run throueh " the program for the f m t tme. T h ~ program s could also be used by students who have no priur knowledgeof smplex tu crankout new factor levels such as those used to maximize the yield of a reaction in an organiclinorganic synthesis class. Before use installation of the disk is necessary. Instructions on how to do this and how to make back-up copies are included in the documentation material. Detailed instructions for the tutorial help to guide the user easily through the program operation. A table of contents in the documentation allows the user to find easily the answers to questions that might arise. Help is also available from the software itself a t various input points. Users with a truly IBM-compatible color monitor will enjoy the ample use of colors during the program. Not only is it esthetically pleasing but also it makes the program easier to run. The program, however, can be installed for use on a monochrome display. Prompts for data input are quite clear and inputs are easy to enter. Gross errors do not ~
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cause execution of the program to halt. The user can also readily change data values a t repeated cheek points. Data files are created for later retrieval and can he password protected. During the program the student is asked to supply the experimental factor level names, units, boundary conditions, starting values. and steo size. In the tutorial these vnlues are all displayed by thr donrmentat i m for the user to input. The tutorial then generates a sample data set of respm5ed. For a real experiment the responses would be supplied by the student. The program rapidly performs the necessary calculations to project the cwrdinates of the new vertex of the simplex which corresponds to the next set of factor levels t o he tried. Uo t o 12 faetzr levels can be handled in any optimization stratrgy using this pro. gram. Even with 12 factors the mlculationu areperformed very rapidly,withina fewseconds. A menu provides the user with the choices of inputting responses, displaying data and results in tabular or graphic form, or halting the program. Students wishing t o learn about simplex with no prior knowledge will find the program of some pedagogical value. To those with prior knowledge the true learning that takes place comes from the output of the program as i t generates the next set of factor levels and in the way that i t stores and presents data. Students were pleased to have a painless way of determining the new factor levels instead of having to calculate them by hand. The documentation is ouite eood in 19 enablmg the student to under;tand;hat gem: on and what are the o b p ~ vcs t of the program. James P. Deavor College of Charleston Charleston, SC 29407 Foundations of College Chemlstry Morris Hein. BrookslCole: Monterey, CA, 1986. xvi 567 pp. Figs. and tables. 19 X 24 cm.
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This textbook intends to instruct students in the basic conceots of chemistw and qualify students ior courses in general college chemistry. It rrmains o revt lor beginning o r preparatory chemistry and srrws its purpose well. I t is difficult not to he enthusiastic about this new edition that begins with eight pages ~of color pictures showing chemistry and chemists a t work. Illustrative tables, graphs, and figures give variety to each page; the text is not tiresome or tedious t o read. Important terms are printed in the margin and two shades of brown highlight section headings, figures, and tables. Precedingeach chapter is a list of learning ohjeetives far that chapter. More than sufficient questions and problems with selected answers in an appendix follow each chapter. Review exercises covering preceding ehapters and interspersed through the hook. At least 20 percent of the book consists of questions, problems, and review exercises. Where quantitative concepts are discussed in the text, clearly worked examples are shown. Significant figures, rounding-off, scientific natation, and S I units are introduced early. Separate sections on how to study chemistry and solve problems will as-
throughout the book makes for a very attractive textbook. The problems a t the end of the chapter are listed by chapter subheadings and are a good mix both in number and difficulty. Opinions differ in the order of treatment of topics in a general chemistrytext. I would prefer to see balancing of redox equations reviewed briefly a t the start of the electrochemistry chapter (Chap. 17). Chapter 9, Properties of Gases might have been placed earlier in the teat because one usuallv encounters eas law erneriments earl", in the ,, lahuratory program. I a l ~ prefer o tu have the Erst law ofthermud~namicsto be pre~ented earlier than in Chapter 12, as the concept of enthalpy change for chemical reactions is very useful through theentirecourse in general chemistry. Sections 16.3 and 16.4 dealing with complex ion equilibria is better placed in the chapter on transition metals and after the section on coordination compounds (Chapter 21.11). Equivalent aelghts and nurmality can be omitted from Chapter 8 and a section on acid-base reacrions using mole and molarity concepts should have been included. It is good to note that the authors have dropped the Kh constant from this version of the text and have treated all ionic equilibria from a K, or Kb standpoint. They do, however, continue to discuss the topics of buffers as either acid buffers or basic buffers. A buffer solution is either acid or basic depending on the K. value and the eoncentrations of the acid and its conjugate base. I would also have derived the HendersonHasselhalch equation (eq 15.9) and showed that i t can be used far any buffer solution regardless of whether i t is either an acid or a basic solution. Energy changes in nuclear reactions could have been expanded t o include not only binding energy but also alpha decay. Binding energy while calculated in MeV per particle (p 826) should also he given in units of kJ per particle. I find i t also convenient t o list in the appendix tables of data such as thermodynamic values, equilibrium constants, and bond energies. New to this text is a software package, The Chemistry Tutor, consisting of six units keyed to the first eight chapters of the hook. Other supplements include a study guide, solutions manual, lecture outline, test file, transparencies, and a microeomputerized testing system. The specific things that I have listed should not discouraee from adoot" anvone , ing this rexr. In general the bwk can be deserihed as "comtortable" and au such, very adequate for trnching and learning. It is obvious that the authors have gone to great lengths to make their book attractive. Many teachers will want to examine it closely. Daniel T. Haworth Marquette University Milwaukee, WI 53233
sist the new chemistry student. Dimensional analvsis is stressed and illustrated in countless solved nrohlems ~~-~ Expanded discussions of pH and solubilit y product and related ralculatimr correct shortcomings of an earlier edition. Joules with the calorie equivalent in parentheses, liters, and tom find general use. As a long-time teacher I was particularly impressed by the 38 pages of appendices. A mathematical review with a worthwhile discussion of graphing and using graphs takes up about one-half of this last section. Other appendices present an interesting solubility table and the periodic table with the new group numbering. Few factual and typographicalerrors were discovered, but a few comments seem necessary about some implications of Lewis dot structures. I t is misleading a t best t o show molecular oxveen with all electrons oaired. ," Cwing the apparent structure would illur. mate one exception to the octet rule. Furthermore, it certainly isn't wrre tc, rhow the dot structure of molecular nitrogen with two three-electron bonds instead of the usual three-electron pairs between the atoms. With over seven pages for discussion of nucleic acids and DNA, i t seems strange that there is nothing on thermodynamics. Although there is discussion of the law of conservation of mass i t is not connected to thermodynamics. There is a reasonable discussion of heat in chemical reactions, but the terms enthalpy, entropy, or free energy are not included. A text like this could describe the idea of a spontaneous chemical reaction in simple thermodynamic jargon. Good sections on water purification and oollutian are included:.however. ~.~~~the current topic i,f acid rain is omitted. Other air pollutants and ph~,tuchem~ral smog likewise are not considered. In spite of the few minor deficiencies, this Sixth Edition incorporates useful changes and additions. I t should attract a wide audience of both students and teachers. Ward Knockemus h~ntmgdonCollege Monlgomery. AL 36 106 ~
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General Chemlstry Principles a n d Structures, Fourth Edltlon James E. Brady and Gerard E. Humiston. Wiley: New York, NY, 1986.xxil+ 972pp. Figs. and tables. 21.5 X 26 cm. $39.95. This well-received general chemistry textbook, now in its fourth edition, has been significantly upgraded with each succeeding edition over the past 11 years. The current edition contains 24 chapters of which three chapters are directed exclusively t o deseriptive chemistry and the other 21 chapters to the discussion of principles with good mix of "chemical" (descriptive) chemistry in these latter chapters. Several major changes are to he noted in this edition as compared t o the previous edition. Atomic structure and the periodic table is now two chapters (Chapters 3, 4), the material on chemical reactions is also two chapters (Chapters 7, a), a n d a new section has been added t o We chapter on chemical honding (Chapter 5) which serves as a prelude to the discussions on ionic and covalent bonding. The black print with blue print subheadings along with a large number of full color photographs distributed
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Elements of Chemlstry R. Boikess. K. Breslauer, and E. Edelson. Prentice-Hall: Englewood Cliffs. NJ, 1986. xxiii 768 pp. Figs. and tables. 21 X 26 cm. $35.95.
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The authors of this text state that it is intended for "students of the allied health (Continued on page A26)
Volume 65
Number 1 January 1988
A25
