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COLLEGE CHEMISTRY.3. A . Babor and A. Lekrman, Assistant Professors of Chemistry, College of the City of New York. Thomas Y. Crowell Company, New York City, 1940. xiv 659 pp. 151 figs. 15 X 23 em. $3.75. This book is a revision of the text of the same title published by Professor Babor in 1929. The authors state that the hook is intended primarily for the use of students who have had a course in high-school chemistry, but that superior students without this prerequisite should have no great difficulty in understanding the text. The reviewer does not aeree that.the same text material can be fully satisfactory for t h c r twodilfcrcnr classesof students. and rondders it for hettcr to write specifically for one of these groups than to attmmpt to include both. The student who has had thorough preparation in an elementary school course in chemistry should he so far advanced that the material which is suited to his needs is far beyond the reasonable grasp - of the heain. ner. The general plan of the book is the same as that of the former edition; hut it has been almost entirely rswrittm in order to include new material, bring the discussion up-to-date, and provide for changes in the presentation. Little material of a purely descriptive nature, except for a review of hydrogen, oxygen, and water, is included in the first twenty-one chapters. These chapt e n deal with the development of the atomic-molecular hypothesis, chemical equilibrium, atomic structure, solutions, and ionization; and they are developed primarily from the theoretical point of view. Eight chapters devoted to the discussion of the non-metals and including a treatment of oxidation-reduc tion follow. There is next a short.chapter on colloids followed by ten chapters dealing with the metals, and three, with organic substances. The usual tables and a table of logarithms are found in the appendix. A series of questions and problems is placed a t the ends of the chapters. The amount of the material included in the text is greater than can be effectively taught in a one-year college course following preparatory chemistry, and is far beyond the attainment of those preparation. hi^ is not in itself have not had this an objectionable feature, provided the material is so presented that selection can be made without loss of continuity in the development of the In some instances, however, expimaideas which are not familiar to the tions are h-d on student. Thus, in the discussion of atomic structure, the encounters the terms "quanta" and "quantum theory," concepts for which he has had no adequate preparation, instances, i t is difficult to determine the reason for the arrange. , paragraph discussing the ment of the topics. ~ h u a~ short abundance of the elements introduces chapter 111 which deals with the atomic-molecular hypothesis. Ideas which have not heen adequately developed by the authors are frequently introduced in the discussion f, important topics. Ionic equations, including the formulation f, complex as page 137, although the topic ions are represented as "Ionization" is not discussed until chapter XIX, heginning on page 259. Again, ionic and electronic equations for reactions of oxidation-reduction, including such an equation as that for the reaction of potassium permanganate with hydrogen peroxide, are written on page 185; but the systematic discussion f, this topic commences on page 341, ~h~ action of the catalyst is mentioned on pages 144 and 148; hut the definition of a is on page 157. hi^ would seem to add unnecessarily to the burden of both student and teacher. The emphasis on industrial processes is not always wen placed, From the text discussion, one would conclude that the reaction of steam with iron is the leading pracess for the preparation f, hydrogen industrially, and that oxygen is prepared from the air by the Brin praeess. ~h~ arc process for the fixation of nitrogen still receives undue emphasis. I n the discussion of oxidation-reduction, the authors give both methods of balmdng the valence number and the ad. equations without attempting to show the student vantages of each. ~h~ emphasis seems to he on the balancing of the equations rather than on the principles involved in and illustrated by the reactions. The reviewer believes that a clearer
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understanding of this topic may be gained through the use of the half reactions developed by the ion-electron method for all of those reactions which are primarily ionic in nature, and of the valence number method for those reactions which are essentially non-ionic. The reviewer considers the development of ionization and the chapters dealing with ionic phenomena t o he clear and well balanced. By showing the applications and limitations of the Arrhenius theory, the way is prepared for a logical presentation of the complete ionization of certain classes of electrolytes. The newer definitions of acids and bases according to the Br#nsted concepts are included but are not extensively applied. These definitions, for example, are not emphasized in connection with the consideration of the common ion effect in affecting the hydrogen-ion concentration, of hydrolysis, and of amphoterism. The descriptive chemistry of the elements and their compounds is presented from the usual point of view. The order of the arrangement of these chapters may vary, hut the discussion within each group is along the conventional lines. For those teachers who wish to develop the subject primarily from theoretical considerations, before the introduction of any considerable amount of descriptive chemistry in addition to that small body of specific knowledge which the student brings from his school course, this book should prove thoroughly satisfactory. By a complete mastery of the material in this book, the student will become well grounded in the basic principles of the subject and will be thoroughly prepared in the prerequisite material needed for advanced work in chemistry. STUART R. BR~NKLEY YALBUNIYBBSZTY
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TO CRYSTALCHIS~Y. AN INTRODUCTION The University of City, 1939, + 381 pp, 113figs, 13
R. C. Evans, New York 21,5 s4,50,
Dr. Evans has taken the available data and theories on crystal Structure, metallurgy, the physics of crystals, and the physical chemistry of compound formation and has woven them into a hook which is so intensely chemical in its outlook that your reviewer started out t o say that it,wa~'obviouslywritten by a chemist for chemists. However. Dr. Evans is not a chemist but and petrolo@stJ a The book starts out by giving the early simple pictures of the various interatomic binding forces, shows wherein these pictures were unsuitable, and then takes up the high spots of the more modern theories. The end results of these theories are set forth clearly without going into the mathematics by which they are derived. The metals are then classified for purposes of discussion into four groups: (1)the "T-group" metals, i. c., the "transition metals." together with copper, silver, and gold; (2) the "A-group" metals, i. e., the alkali and alkaline-earths, and beryllium and magnesium; (3) the more metallic "B,-group" metals, i. c., roughly those of thesecond, thud, and fourth groups @ the periodic table; (4)the less metallic "Ba-group" metals, r. e., roughly those of the fourth, fifth, and sixth groups. The crystal structures of each of these groups are examined to see what chemical information can he gained from them, and then the various types of alloys. A-A. T-BI. T-Ba, A-B,. A-B*, and B-B, are similarly discussed. Chapters follow a n homopolar compounds, ionic compounds of the isodesmic, mesodesmic, and anisodesmic types, ionic compounds containing hydrogen, and this is done with a line sense of compounds. balance between the metallurgy, physics, and chemistry which must he considered simultaneously in such a discussion. The style of writing is simple, clear, and unambiguous. The hook is remarkably free from errors. Lest anyone should think that it is too elementary, it may he said that although the book makes good and connected reading by itself, it also serves as an introduction t o a bibliography which includes as much highbrow mathematics and physics as even the most fastidious could wish. W u e e ~ P. ~ nDAVEY PerNsuLvnr*rA STAT.
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