THE COLLOID CHEMISTRY OF SILICA AND SILICATES
Ralph K. Iler. Cornell University Press, Ithaca, New York, 1955. xii 324 pp. 62 figs. 20 tables. 16 X 23.5 cm. $5.50.
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T m style and approach of the nine chapters in this book reflect their origin as the George Fisher Baker nonresident lectures delivered a t Cornell University in the spring of 1954. "In the lectures and in this book, a n attempt has been made to assemble and correlate information relating to the behavior of silica. and silicates in the colloidal state so as t o present a coherent picture of suoh pertinent phenomena as solubility, formation, and behavior of colloidal particles and surface chemistry of the solid phase. I n addition, since there did not seem to be available a general survey of the occurrence of soluble and colloidal silica, in biologicsl systems, the brief review presented in Chapter I X seemed to be in order." The attempt a t a coherent theory leads to a refreshing willingness to speculate, and on page 36 Iler rejects the firm phase equilibrium approach, since "this view does not throw any light on the mechanism by which the polymerization of silicic arid takes place . . .," with the hope, on page 26, that "assuming the proper structure of the polysilicate ion, may eventually permit a calculation of the average molecular weight and size distribution of the polysilieste ions in sodium silicates of different Si0~:Na.o ratios." Chapter I, The Silica-Water System, reviews what is known of the solubility and deposition of SiOa in water. Chapter 11, Soluble Silicate, takes up in detail the speculative theory of structure in solution whieh Vail avoided in his recent monoq a p h of the same name. Chapter 111, The Chemistry of Silieic Acid, continues in the same vein to relate a wide selection of referenoes on the palymerization and reactivity of silica in solution. I n the discussion of salting-out phenomena, this reviewer was surprised that the more modern theory of coagulation, used on page 110, far example, was not employed here. Chapter IV, Esters of Silicic and Polysilicic Acid, is a short chapter summarizing the characteristic structures of siloxsne polymers. Chapter V, Colloidal Silica, covering sols with particles in thc one to 100 millimicron range, and Chapter VI, Amorphous Gels and Powders, reflect the author's work in this field and arc the most rewarding in the book. A good working interpretation of the preparation and properties, with a brief resume of uses is presented. On page 119 there is a n error in the dosage of activated silica by B:L~BR in treating water. At least 60 lbs. of silica per million gallons of water, and usually more, is needed. Also, the rcference to "ferrous sulfamate" on the same page should r e d "ferric sulfate." The qucstion of the existence of true silieic acids is not clearly settled (pp. 154-6). There seems to he good reason for assuming the formation of definite crystals by exchange from crystalline polysilictltes. The so-called sodium tetrasilicate might have been mentioned in addition to sodium disilicste and tho various mineral silicates. On page 160 there is a rather obvious reversal of Weiser's differentiation of gels and precipitates. A gel enelose~ all the liquid. Chapter VIII, Colloidal Silicates, is a fine review of the basic properties of clays, zeolites, etc., im related to their structure, and in particular includes an excellent discussion of tubular silicates illustrated with electron micrographs. Chapter VIII, Surface Chemistry of Silica and Silicates, is related t o the SiOH
group in a standard approach. A similar review of the literature on silica. used sn a grease filler and the activity of catalytic siliceous gels is probably not available elsewhere. Chapter IX, Silica, in Living Organisms, also brings together in a review, many references not duplicated elsewhere which should be useful in suggesting further investigation. Dr. Iler has sceamplished a welcome compilation and correlation ai a wide range of investigations involving silica. He has succeeded in presenting the results in a. roesonable relntianship whieh should increase the insight of those interested in the chemistry of silicates and silica. sols. The high quality of the 62 illustrations, the absence of errors, and the typography should also be mentioned. P X ~ L A ~ Z L FQFuI~~ n Am COMPAI~P",L*"*LP",*. PENNBYLYANI*
JOHN H. IVI1.I.S
GENERAL CHEMISTRY
L. E. Steiner and 1. A. Ccmpbell, Professors of Chemistry, Oberlin College. The MacmiUan Co., New Ymk, 1955. x 673 pp. 87 figs. Tables. 16 X 24 cm. $6.50.
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OF THE many new texts of general chemistry t h a t have appeared since World War 11,only a femersn hecalled exceptionalin character. This volume definitely is in that category. I t should be on the study desk of every teacher of general chemistry to show t h a t new approaches to the teaching of general chemistry are possible. The volume is a. definite break with many of the accepted traditions of teaching general chemistry. Many teaehers should be challenged to try the volume in their own classes. In this text, chemistry is presented ns a. science. The student, is expected to think and learn rather than to merely memorize and possibly think. This is whieved "by continual emphasis on the inlerprelation of properties and reactions in terms of structural relationships." These structural relrttionships involve not only electronic structures of the elements and their eolnpounds hut also bond lengths and angles. Tho mere deaoriptive aspect of ahemi~tryis de-emphasized. Reasons for significant properties are continuously presented. T h u ~ ,the greater rate of solution of sulfur dioxide in water as compared with carbon dioxide is ascribed to the fact that water can react with sulfur dioxide molecules more readily for geometrical reasons because it has a "bent moleeulc" (page 410). The brittle micas itre harder than the soft micas because the silicate "sheets are held together by C s + + ions which are smaller and more highly charged than the K+ ions" (page 549). Frequent use is msdo of dram-ings of scaled models. On page 363 there are drawings to shorn molecular structure t o scale of nitrous oxide, nitric oxide, nitrogen dioxidc, and the nitrate ion. If molecular models are not used, formulas are frequently written to bring out structure. Thus, sulfur and phosphorus are indicated by the formulas S9 and P., chlorie acid is given tho formula HOC102, not HC1O2, and perchloric acid ia HOCI08, not HCI04. This volume proves that a new order of topics which breaks n i t h tradition can be used t o present effectively a sturdy framework for the study of chemistry. Thus, after a. preliminary discus~ionof the principles of chemistry, the discussion of water is presented in Chapter 5 in terms of the structure of the water molecule. The atmosphere is considered in Chapter 6. C h a p ter 7 deals with carbon and elementary crystd chemistry. The
VOLUME 33, NO. 1, JANUARY 1956 structure of hydrocarbons, carbon monoxide and dioxide, and fuels are presented in Chapter 8. The study of gases and kinetic theory lead to a systematic consideration of the periodic table in Chapter 12. This includes the long form of the table showing the relative sizes of atoms and ions. Nuclear structure comes in Chapter 13 preceding the electronic structure of atoms (Chapter 14). The discussion on types of chemical bonds in Chapter 15 is superbly done. This is enough to indicate that the authors have heen building a strong foundation for their presentation of elements and compounds. The first elements t o he studied thoroughly are those of the sulfur family. The study of the elements and their important compounds is always done in terms of family groupings in the periodic table. However, the cyclical presentation of the fundamentals of chemistry continues throughout the volume. Thus, there is further study of radioisotopes and nuclear changes in Chapter 21. The volume closes with 61 p a p devoted t o carbon compounds, including important hormones, vitamins, trace aspects of biochemistry-nutrition, elements, &-and such topics as carbohydrate metabolism. The student who takes no more chemistry will have s. good introduction to organic ehemistry. The authors have not hesitated t o "ditch" mueh of t h e traditional ttreatment of many topios and terms in chemistry which are not in line wit,h modern concepts or modern trends in the teaching of chemistry. Hence, they consistently speak of "molar weights" and "molar volumes" rather than the outmoded and objectionable G.M.W. and G.M.V. The treatment of atomic weights includes adiscussion of the unit for actual atomic weights, of the average ma88 of oxygen atoms or the "avogram"grams. The conventions as to electrode poten1.6601 X tialp follow the IUPAC reeommendations rather than the current American practice. Consequently, the half-reactions are arranged in an order of increasing tendency for the ions t o gain electrons uit,h theoxidized state on the left. Thin reverses thesignof t,he st,andard potential as usually given in American texts. The mort vigorous oxidizing agents me a t the left and bottom while the most vigorous reducing agents are a t the right and top of tho oolumn of half-cell reactions in the e. m. f. series. The authors have been very courageous in adopting this convention in that it is a complete departure from current practice. Moreover, there is mueh t o be said in favor of their convention. I n effect they are using tho standard hydrogen reference electrode t o establish hoth the magnitude and the sign of all electrode potentials. This potmtial is the e. m. f. of a cell which combines a given half-cell reartion with a. standard hydrogen electrode pleced on the left. This follow^ the reeommendations of the Commission on Phyaieo-Chemical Symbols and Terminology and the Commib pion a n Electrochemistry of the International Union of Pure and Applied Chemistry. The format of the volume is pleacing and the illustrations are oxeellent. The reviewer noticed very fow errors. The most seriou~criticism is one t,hat can be relatively emily removed in the second printing. The indexing is inadequate. Thus, such important termsa? atomic number, A number, Z number, hyporhloroua acid, hydronium ion, hydrogen ion, and pH were not found in the index though in use in the text. With the incorporation of mueh new material on structure, some material usually presented in general ohemistw texts has had to be cnrtsiled or omitted. Thus, the reviewer found no d i s cussion of pH or normal solutions. The authors frankly admit in their preface that teachen using this book will have t o present selectively only certain sections of the volume. I n this way the range of content can vary from in~tructort o instructor, but the oontinuoua emphmis on the relations of properties and uses t o electronic and geomctricitl structure should result in a. total pattern for viewing chemistry that students can apply long after t,hey have finished their first course in chemistry. The reviewer repeats a part of his first paragraph: This is an exceptional text. It should he in the hands of every teacher of general chemistry. CONRAD E . RONNEBERG
DEN~O u~zvensmr X GR*NVILLE, OHIO
LABORATORY EXPERIMENTS IN GENERAL CHEMISTRY
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I. A. Campbell and L. E. S e i n e r , Professors of Chemistry Oberlin College. The Macmillan Co., New Yark, 1955. viii 216 pp. 3 2 figs. 20.5 X 27.5 om. Paper bound. $3.
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THIS m s n u d i~ designed t o serve as the basis for two semester? of lahorrltory work in general chemistry. The experiments me well designed to bring out (1) fundamental principles of chemistry, such as the determination of molar weights of gases, liquids. and soluble solids, the determination of equivalent weights of met& or acids, etc.; (2) the significant reactions and properties of inorganic elements and compounds; and (3) the chemistry of semimicro qualitative analysi-not less than 12 weeks. This manual can be used with any college general chemistry text. Some of the principal features of this manual are that: (1) the student is expected t o design experiments, with guidance, and make discoveries for himself rather than verify what he already knows; (2) the experimental "setups" are very simple and require no great manipulative skill on the part of the student; (3) many of the exueriments are onlv hrieflv outlined comuelline the student t o work out his own procedu"res; (4) detaileh disc&ons of the theory back of individual experiments are largely absent, thus requiring a maximum of teaching or reliance on the class work; (5) there is complete absence of a "work-hook formatuthe student is expected t o write up his own reports; and (6) a large fraction of the experiments are a n a test-tube s c a l e f r e quently quite novel and pertinent, like the use of ammonia solution on heated copper oxide t o illustrate reduction by ammonia. The experiments are very carefully planned in sequence t o serve as the experimental basis for any general chemistry course. The experiments oorrelate the work of the entire year, with about one-third of the y e a devoted t o simple qualitative analysis. This manual should be examined b y all teachers of general chemistry who wish t o break away from the loek-step, workbook type of manual and have the student assume some responsibility for his own work in the hhoratory. CONRAD E. RONNEBERG DEN~O UN I Y E R ~ I T Y
G n m v r m s , Onm
Edited by F. Rodt. Elsevier Publishing Company, Houston, 1954 xndx 664 pp. 18.5 X 25.5 cm. $36 for set subscribers, $42 for subscribers to Series 111, $48 for single copy.
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EARLIER volumes of Elsevier's Encyclopaedia. have received many well deserved complimentary reviowa. This supplement to Volume 14 maintains tho standards of excellence which have been set previously. Volume 14 originally covered the literatureof steroids and triterpenes up to 1936. I n the decade 1937-46 which the Supplement covers, the great expansion of the literature of steroids makes it impossible to cover this field alone in one bound part. The present volume includes the nor-steroids, thesteroid hydrocarbons, and their halogen, nitrogen, and unsuhstituted monohydraxyl derivatives. The nor-steroids are compounds in which one or two of the six-membered rings of the 1,2-cyclopentenophensnthrene ring system have become five-membered. It is stated that "the literature has been consulted up to and including 1946, the literature concerning the structure and configuration of compounds up to 1954." The coverage is, however, more complete than this statement might imply. The practice has been continued of including literature references relating to structural changes up to the latest possible date, and those deal-
