book reviews Acids and Barer
Russell S . Dmgo, University of Illinois, Urbana, and Nicholas A. Malwiyoff, Pennsylvania State University, University Park. D. C. Heath and Company, a division of Raytheon Education Campmy, Lexington, Mass., 1968. vi 121 pp. Figs. and tables. 14 X 21 em. 51.95 paper.
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On page 2 the authors define a Lewis base as "any substance which has electron density that, can be shared with mother substance in a chemical reaction" and a Lewis acid as " m y substance capable of accepting electron density from a Lewis base." The remainder of this first chapter is devoted to interesting discussion of wellchosen resct,ions that can be described or interpreted in terms of the Lewis acid-base definitions. Chapter 2 begins with a useful discussion of the ambiguities involved in selecting general criteria for acid-base strength (another good example is given in Chapter 4), and then turns to thermodynamic considerations, which form the weakest part of the book. Thermodynamic quantities and equations are not defined or derived in any formal fashion that is appropriate for rehders unsequainted with the subject, nor are relevant equations merely written down as appropriate for readers who have already studied thermodynamics. Instead, equations are given wilhout d e r i v e tians, but are nceampanied by nan-mathematicel defieriptions that I think are L I clear znd sometimes misleading. Examples (pnges 19-20) are tho following: "The free energy of x species represents the work whieh is stored in that species." and "The reversible processes are important because only from them can we obtain the maximum work functions whieh characterize the fundamental properties of the system." The discussion of standnrd states is entirely inadequate, particularly for solutes, which in turn means that the discussion of activity coefficients is inadequate. There are such explicit thermodynamic errors as (page 87) "Despite this temperature dependence of AH", a plot of log K versus 1 / T is linear (authors' italics!) bccause of compensating changes in ASo." On page 57, the variation of activity coeffic~entwith temperilt,ure is incorrectly given in t,erms of the heat of solution (rather t,han the heat of dilution). Less important, but bothersome to such inexperienced readers as the "advanced freshmen" referred t,o in the Preface, are such inconsistencies a-the use of AP' after hasing stated (no reason given) that AG" is preferred, and citation of an incorrect v d n e of It (incomplete units). In spite of these weaknesses, the authors have made considerable interesting use of enthall~y cycles in interpreting acid-base reactions. I t is my opinion that the material covered in Chapters 1-3 (largely devoted to acid-bnue reactions in the gas phase and in poorly solvabing solvents), without the itrtrodoetion to t,hermodynamies, woidd have been +n interesting paper for THIS JOURNAL. The more qtdilstive pnrt,3 of Chapter 4, largely devoted to acid-base
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equilibria, in waler, might well have been included. In canneet,ion with acid-base equilibria in water it might be noted that "Acid-Base Equilibria" by E. J. King (Pergamon Press, 1965) is in a class by itself for students and experienced researchers alike. L. G. HEPLER University of Lcthbridgo Lethhridgc, Alberta
Instrumental Methods of Chemical Analysis
Calm Ewing, Seton Hall University, South Orange, New Jeney. 3rd ed. McGraw-Hill Book Co., Inc., New York, 1969. x 627 pp. Figs. and tables. 16 X 23.5 em. S11.50.
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The third edition of this text ret,ains for the most. part,, the sequence of topics introduced in the second edition (reviewed in THIS JOURNAL, 37, A750 (1960)) hut has been iucreased by some 175 pages. Completely new are the generally wellwritten and up-to-date chapters on Fluorimet,ly and Phosphorimet~y (14 pages, reflecting the current high level of interest in these studies); Flame Spectroscopy (19 pages, with its principal emphasis on atomic absorption); and Gas Chcomat,ogrs;phy (25 pages). Concerning this last chapter, if a novice were to tnrn directly to i t he might wonder ahorrt the lack of bheory and terminology; ~ m fortunately, no reference is given to the preceding new chltpber on Int,roduction to Interphase Separations (14 pages) where t,his informstion is to be fonnd. Further, devot,ing 10 pages to a discussion of detectors and hnt, t,wo pages to qualit~tive and quantitative analysis seems a hit disproportionate. Three otber chapters beating new titles deserve comment. These w e the Scattering of Radiation (12 pages, inclnding nephelometry, turhidimetry and Raman spectloscopy); Liquid Chromatography (19 pages); and Electrical Separation Methods (8 pages, principally eleebmphoresis and electmehmmntogrctphy). In each case those chapt,ers have been constrocted, in part, flom material formerly scattered throughout seveld chapters in the previous edition. However, for each, too, the basic material has been rewritten, expanded, and imprnved hy the addition af new seet,ions (those on gel permeabkm and thin-layer ehramstogmphy in the chapter on Liquid Chmmatography as one example). Although their t.itles remnin unchanged, certain chapters have been so ertensively revised xs to present an almost, entirely new appearance. The Absorption of Endirttion: Infravxl, Mass Spectrometry, AIagneiic Resotnance Spectmxop,v and Thermometric Methods rh&ers, especially, have been almost eampletely rewritten and updated, and the many new tables and figures add much to their usefolness. Of the remaining chapters, a t least three have been noticeably imprnved through
their revision and expansion. Over .5O per cent of the content of X-ray Methods, and Radioactivity as an Anslyt,ical Tool is new, while iu the chapter on Voltammetry, Pal~rographyand Related Techniques one finds that. tho discussions have been gmatly strengthened by rewriting, t,hrough the addition of several new figures, and by the inclusion of a nnmher of new topics (cyclic voltammetry, chronopotentiumetry, and so on). I t would he incorrect to leave the impression that none of the other chapters has received the aut,hol.'s attenbion. For example, in Chapter 10, to polxrimetry is now added a brief section an optical rotatory dispersion; t,he treatment of membrane electrodes has been expanded in Chapter 12; and Chapter2.5, General Considerations in Analysis, has 8. fresh look about it. Electronic Circuitry for Analyt,ical Instruments (Chaptet.26) is a n area in which Professor Ewing is a recognized expert. I t is not smprising that ill this new edit,ion there are now included discussions of FETs, MOSFETs, opemt,ional amplifiers, and so on. For one not familiar with the second edition, however, what may ,not be evident. is t,he extensive reorganizing and rewriting of this chapter that was done to present, in necessal.ily highly ahridged form, a more nndorstsndnble and useful treat,ment. Of the 25 Isboraboly experiment,^ in this third edition, four are new, six represent, major revisions of second edition exercises, while the remaining 15 have been carried over with bnt minor, if any, changes. One thivd of tho approximately 100 prohlems are new, and a problem "Sohrtions hlnnusl" is now avnilahle from the publishers. Bibliographic Notes fonnd at the end of each chanter i n thc second edition have now disappeared, and with them reference to such works as Kolthaff w d Lingane's "Palarography" in the chapter dealing with this topic (cited hy Ewing in the second edition as being ". . .most detailed, especially in it,s theoretical aspects"); and to L i n ~ m e ' s"Electroanalytical Chemistry" in the chapter on Potentiamctry. Time does not dldl the usefdness to the beginner of these and similar bnsie treatises. Furthev, in the t~.ansitianfrom the second to the third edition, several credit references arcompanying tables, problems, figwca, and literainre examples selected f m discnssion have heen deleted. Thin is regrettable, for if the text user now wishes to probe flnther, he e m not easily do so. To the credit of the author, most malcrial taken flnm othw sources has heen docnmented, and the general updating of vefewnces is impressive. The new type style and the redrawn diagrams and graphs are especially plensi n . No t,ypographical e l w w were deterted, unless one exists in the caption of Figure 3-8 on page 65. At the wavelengths given, hoth nuves (a) and (b) show the same type of deviation from Beer'i; law and this was not intended. H. W. %mono Tiniuersill, of Pittslnrgh Pillsbnrgli, P a . 16g10 (Cmlinurrl a page ,4136)
