Experiments in Inorganic Chemistry (Long, J. S.)

The exercises are divided into three groups illustrating: (a) "principles of chemistry"; (b) "preparation of elements and compounds"; and (c) "reactio...
3 downloads 0 Views 1MB Size
The reviewer regrets that he cannot recommend this book for use as a text. It is not systematically arranged, well-balanced, nor teachable. Indeed, the author says: "The student specializing in chemistry should, of course, read in conjunction with this book mauv others." He also savs: "This will not be found to be a 'teachable' book; a teach;ble book is a learnable hook. and that is a most dangerous educational weapon. Chemistry is not a teachable suhjcct; it is a thing to be struggled with."

CHEMISTRY. J. S. Long. Ph.D., E X P E ~ N TINS INORGANIC Professor of Inorganic Chemistry, and R. D. BiUinger, Ph.D., Assistant Professor of Chemistry, Lehigh University. Times 298 pp. Publishing Co., Bethlehem, Penna., 1932. viii 26 Figs. 13.5 X 21.5 cm. $1.75.

+

The number of pages given in the above description is same what misleading. The printed pages number only 149; one side of each sheet is left blank. This laboratory book is designed for one semester's work but a sufficient number of experiments is given to require almost one and onehalf semesters for the average student. It is intended that beginners might omit some of the more difficult experiments and the student from a good high-school course might omit the simpler dnes. Hence this manual will snit both types of students. All of the work usually included in an elementary course is covered here with the exception of that on the metals. Some of the experiments found here and not often in other manuals are: velocity of chemical change illustrated by the HzSO. HIOa time reaction; chamber process for HSO.; preparation of AsH8; a measure of catalysis by the decomposition of HZ%; preparation of Hg(CNS)%. The book is well written and in s~fficientdetail so that it should he easy to follow. It might be better if a few more illustrations were given. Each experiment is followed by an excellent series of questions. C. E. WHITE

+

umms1ru 0s M*FSL*ND COGLEG& P A R K , M D .

E X P E R I ~ N T ACHEMISTRY L FOR COLLEGES.J . Allen Harris and William Ure, Assistant Professors of Chemistry in the University of British Columbia. McGraw-Hill Book Co., Inc., New York and London, 1932. x 192 pp. 21 Figs. and 9 tables. 20.5 X 26.5 cm. $1.25.

+

The exercises are drawn up for fust-year chemistry students. "The necessity of getting away from the methods of laboratory instruction in elementary chemistry in which the student is asked to perform a large number of short and chiefly qualitative experiments, ending in the sink, is becoming apparent to most laboratory instructors. Such experiments are better suited to the lecture table, and it has heen our experience that the interest of the student can hest be aroused and maintained by giving him a definite objective to attain during each laboratory period, whether it be the quantitative testing of some chemical principle or the careful preparation of some interesting compound. The experiments have also been carefully chosen so that during their execution the student absorbs a considerable knowledge of the chemistry of the process along with valuable experience in technic (such as fractional crystallization and distillation), without the need of separate experiments purporting to illustrate these operations but giving no indication of their importance or value in general chemistry." To the best of the reviewer's knowledge, the hwk is probably the 6rst of its kind lo appear on the market for all first-year chemistry students. He does know of two other manuals with the same numose in mind. hut intended -- for sophomore stndents or students who have had one year of high-school chemistry. Nevertheless there is a need for this kind of manual. The boak contains 22 exercises, each "preceded by an iotrodnctory section which discusses the field illustrated by the experiment, together with the theoretical considerations involved."

. .

These discussions are of excellent quality and make possible the use of this hook with any standard textbook for first-year chemistryalthough it should be pointed out that there are no textbook references in the hook. The reviewer's estimate of the amount of laboratory time required for the completion of these exercises is about 90 hours. A list of 38 typical chemical prohlems is also included. In these days of economies, it is of interest to note that the authors "have found it quite feasible t o subdivide a laboratory section into four groups of 20 each, each group working on an entirely different experiment." The principle involved is sound, hut the opinion of other experienced teachers is that a group of as many as 20 students working together with one set of apparatus is anything hut wholesome. The leaves are perforated far ready removal from the book and triple-pnnclied for re-filling in any standard notehwk rovera convenient feature. Same of the diagrams are extremely formal in appearance. For example, the student may find a second look a t Figure 17 necessary in order to assure himself that one item in the set-up is t o be of rubber tubing and not glass tubing. The diagram of the common gas burner appears to have been made by fallowing the cut-out design found in s celluloid Harcourt stencil. The beakers have an unusual angularity at the top. The amount of glass tubing required in Figure 14 is uneconomical. The instructions in the diagrams are excellent with a few exceptions, such as found in Figure 17 which calls for sulfuric add whereas the descriptive matter requires hydrochloric acid. The exercises are divided into three groups illustrating: (a) "principles of chemistry"; (b) "preparation of elements and compounds"; and (c) "reactions of electrolytes." In the main the exercises are well chosen. From the discussion it is a little dEcult to understand why there are two adjacent "high-temperature reactions," preparation of potassium permaganate and chromates and dichmmates. Quite a few statements are misleading to the discerning student. On p. 3, "By concentration, we mean the amount of substance present per unit volume." "Two kinds of apparatus are to be used far weighing," yet the two kinds described are merely balances of different sensitivity. "Check your weight by counting the weights." The concept of mlal as found on pp. 3 and 160 in particular is certainly not that of mast chemists. The reader might easily believe that a mrmal solution is the only kind of standard solution. The symbol E representing an electron is first used on p. 92 and the legend is given on p. 100. The use of Arabic instead of Roman numerals for representing valence is to he commended, although there is a reversion on p. 76. In several instances the valence is placed a t the side of the symbol. It is quite comfortine - to 6nd the concentration of acetic acid as the illustration of frmtional distillation instrod of the time-honorrd nlcohol. The use of Na9C02 instead of NaCHOa fur standardization work is perhaps not so good, considering the fact that the remaiudcr of the exercise is to be done with considerable accuracy. The hook should be on the desk of evetv teacher havine laree groups o' students who hove had at least onc year of high-school chcmistrv, e t e n though a number of the pracedurcs arc doubtlers quite familiar to many teachers of first-year students.

- -

ELEMENTARY QUALITATIVE ANALYSIS. J. H.Reedy, Associate Professor of Chemistry in the University of Illinois. Second edition, McGraw-Hill Bwk Co.. Inc., New York City, 163 pp. 13 Figs. 20.5 X 14 cm. $1.50. 1932. x

+

The purpose of the author in the second edition of this boak appears to be to place in the hands of the student a set of reliable laboratory directions and, a t the same time, leave ample opportunity for interpretation of results. Part I takes up the analysis of the cations. Directions far preliminary tests are first given which are followed by directions