book reviews The remainder of the text involves a series of fwp "tricks" w h ~ usc h varltus chemic~l i y t r m i , in a magic-likesetting, topresent to a n audirnre of potrntinlly widr-ranging composition, some interesting and colorful chemical reactions. The format used is a discussion of the system in a very general manner followed by details of materials and chemical preparations necessary, and finally the details of oresentation whieh include the auth~rs'su~gkstions for patter t o be used in a performance of these demonstrationsfor a general group. Trick 1 utilizes phenolphthalein, metanitrophenol and thymolphthalein to develop the full spectrum of colors and is averysimple and reliable demonstration that might be used by students or chemists of wide-ranging backgrounds. The only negative comment I have concerning this demonstration is the suggestion of drinking the mixture which the authors (two of whom are MDs) explain is quite safe in its composition. The suggestion that performers of this demonstration personally consume materials involved in chemical reactions, with the potentials for poisoning, isof great concern. I feel theneed to recommend strongly that the authors delete this portion from the text. Trick 2 uses indicators carefully chosen so that the addition of acid or base would lead to a specific color an demand. The major difficulty with this demonstration as it is currently written is the authors' reference to the chemical species called "hexamethoxwed" which is not commerciallv available. and whose prrpararm require suiticirnt rhrmlc.d exprrt~srthat it u < uld m,t be pcsid T ~ authors P s h l c cur reit. it,, x ~ n ~ r us:age. suggest the use of thymol blue to prepare the red color necessary in strongly acid solutions, but do not give any specific directions for this since they have elected to use the "heaamethoxyred" in this region. Given the difficulty of preparation and lack of commercial availability, the inclusion of directions far the use of the thymol blue would enhance this demonstration significantly. Trick 3 is the well-used luminol reaction with the addition of eosin and fluorescine to portions of this material to provide some color variation. This demonstration works quite well and the variations that the authors suggest appear to be successful, although this reviewer had some difficulty in obtaining much color with the eosin system. Trick 4 includes aseriesofcloek reactions that result in colors which include red, yellow, blue, and black, andarevariationson the iadate-sulfite clock reaction often used in freshman chemistry. Nevertheless, this system constitutes one of the more interesting and well-developed systems within this text, and constitutes one area where more activity might lead to a wider range of colors and, therefore, broaden the utility of this particular system. Trick 5 offers the most unique system in the text which is a multicolored clock reaction which produces in turn most of the colors of the spectrum, except green, although not in the spectral order but in the order of blue, violet, black, red, orange, yellow, and then colorless. This system has the additional A450 I Journal of Chemical Education
advantagr that it may br regenerated easily by adding n small amount of r d i u m sulf~tp to reproduce the colors in sequenee once again. The authors include a brief discussion of other "magic" changes which indude the treatment of a flae which has been oresoraved or minted A h ohenolohthnlein.and thymolphthalein ta provide the proper colors when sprayed with a mildly basie solution. This is followed by spraying with an acid to remove the colors which can be reproduced again by spraying with base. Theauthors do recognize the problems of safety with spraying these acids and bases, and, in my view, could readily delete this wholeseetion from the text with no " ereat loss. The use~~fdem~,n.itrutions forgeneral aildiencrs to m e r e i t them in chemistry, to provide special riirrti u hwh chemiral systems can effectively demonstrate are incarporated moderately effectively in this brief text. I have some concern which I have expressed in my review about certain sections and suezestions made in this text. but I feel
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also feel that it is not an appropriate resource, in its current form, for use by individuals who lack some background in chemistry. George L. Gilbert Denison University Granville, Ohio 43023
Solving Problems in Chemistry: With Emphasis on Stolchlometry and Equilibrium. Second Edition Rod O'Connor, Charles Mickey Altan Hassell. Harper & Raw, Publishers, New York, 1977. x 458pp. 21 X 28 cm.
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This book is logical and builds in a step by step fashion through 15 units. If students can work their way through the relevant problems of each unit, then they most assuredly will become proficient in the mathematical sense of the basic chemistry as applied to their majors. The authors are to be commended for trying to m i t e a t two levels (i.e., for both the average and above average student), and for presenting problems in each unit in four different categories: (1) agriculture and marine, (2) biologyand medicine, (3)industry, and (4) environment. This enhances and enlarges the value of the bwk-allowing students to work relevant problems in their own areas of interest. Pre-testing, and after the exercises, a self-test (in each unit) is also a good idea. I t immediately informs the students of their strengths and of their shortcomings. However, for success, the student should h;we had tor is rurrenrly having, rxpmure I
