V O L U M E 2 1 , NO. 9, S E P T E M B E R 1 9 4 9 used, the totsl chloride was likewise determined gravimetrically. Sr'ns porous porcelain filtering crucibles were used. RESULTS
The data in Table I were used to calculate the distribution coeKcient. All equilibrium concentrations are calculated to mc:", per liter. Complete ionieatition of the hydrochloric acid in the water phase was assumed for calculating the constant in Tahle I. The ohloride concentrations in Table I1 are total chloride, and i t is assumed that both the acid and salt are completely ionized iii the water phase. The constants calculated for 'Ton products" ranging from about 0.035to 3.2 in Tahlcbles I and I1 arc in reasonably good agreement. In ordex to test the cornplcteness of separating acetic acid from hydrochloric acid by controlling the hydrogen and chloride ion products, the following experiments were performed: A mixture of aqueous acetic acid and hydrochloric acid was neutralized to pH = 1, using a Fisher titrimeter. The ester
22.
115s was then added and the regular procedure was followed. Analyses of 20-ml. pipetted portions showed 0.351 M total chloride in the aqueous phase and 8.7 X 10-4 M hydrochloric acid in the ester phase. By calculation, the amount of hydrochlorio aoid in the ester phase is 1.12 X 10-8 if the value K = 3.4 X lo-* is used; hence the agreement is satisfactory. A seaond similar ,mixture was neutralized to pH 2 before extracting with the ester. Here the amount of hydrochloric acid from the ester sample gave only B faint qualitative test as silver chloride and was too small to he determined grwimctrically. Finally a mixture of 0.5 M acetie acid and 0.5 M sodium ohloride was extracted. In this ease a positive test for chloride from the ester sample was questionable.
It is logical to assume that other similar weak organic acids can be separated from hydrochloric acid by this method. LITERATURE CITED
(1) Pagel, H. A,. sod McLafferty, F. W., ANAL. C n e ~ . 20, , 272 ( 1948).
RECE~YE August D 4. 1948.
Uranyl Nitrate Hexahydrate, UO,(NO,),.GH,O
Excellent crystals of uranyl nitrate hexahydrate can be ohtained from either water or alcohol. Care must he taken to avoid crystallization of the anhydrous salt, becawe the hydrate is stable only at low temperatures. Either of these two phases may be ohtained on a microscope slide; the hydrate only in the presence of excem water.
Principal Lines Armour
d
I/Ic
d
Hanawslt
Armour
I/II
Hanawalt
Figure 1. Uranyl N i t r a t e Hexahydrate Left. Crystal%from water on a mioroaoope slide Right. Crystals from fusion, crossed Nicols
CRYSTAL MORPHOLOGY (determined by W. C. McCrone). Crystal System. Orthorhombic. Form and Habit. Plates and tablets usually elongated parallel to c. The crystals show hrachypinacoid ( 0101; macropinscoid (100); maorodome(011); and bipyramid (111). Axial Ratio. a:b:c = 0.877:1:0.609; 0.874:1:0.609 ( 4 ) ; 0.8737:i:n.6nss (e). Intorfacid Angles (polar). 101 A io1 = 59O 30'; 011 A nil = 62" 40'. X-RAYDIFFRACTION DATA(determined by W. C. McCrone). Space Group. Tihl' (3). CellDimensiansb a = 11.58 A,, b = 13.20 A,, = 8.04 A. a = 1 3 . 1 5 A . , b ~ 8 . 0 2 A . , c = 1 1 . 4 2 A . ( S ) .a = 7 . 9 3 A . , b = 1 1 . 4 5 A . , e = 13.01 A. (1). Formula Weights per Cell. 4. Formula Weight. 502.18. Density. 2.73 (x-ray); 2.807 (1); 2.742 ( 3 ) .
a
b
Figure
2. Orthographic Projeotion of Typical Crystal of Uranyl N i t r a t e
Hexahydrate
OPTICAL PROPERTIES (determined by W. C., McCrone). Refractive Indexes (5893 A,; 25" C.). a = 1.482 + 0.002. B = 1.494 A 0.002. = 1.572 * n.002. 6 = 1.497(4).
1152
ANALYTICAL CHEMISTRY
Optic +I Angles (5893 t i . , 25’ C.). 27.’ = 46 44 ( 4 ) ; 2E = 72 . Dispersion. u > T (weak). Optic Axial Plane. 010. Sign of Double Refraction. Positive, Acute Bisectrix. c. Molecular Refraction ( R ) (5893 A.; 25’ C.). = 1.515.$ R (calcd.) = 55.9 (if R for the uranium atom is assumed to be 11.8). R (obsd.) = 55.9, Color. Yellow. P1eochroism. = light = a yellowgreen. FUSION DATA (determined by W. C. McCrone). Uranyl nitrate hexahydrate melts a t 60’ C. and crystallizes O
a
readily on cooling as rods elongated parallel to c. All orientations perpendicular to c are shown; therefore all views show a positive sign of elongation. Only very rarely is it possible to find an optic axis interference figure, as 2V is small and Bz. = c. LITERATURE CITED
Clark, G. L., J.Am. Chem. sot., 46,379 (1924). (2) Groth, “Chemische Kristallographie,” Vol. 2, p. 142, Leipzig. Engelmann, 1908. (3) Pauling, Linus, and Dickinson, R. G., J . Am. Chem. SOC., 46, 1615 ( 1 924). (4) Winchell, A. N., “Microscopic Characters of Artificial Minerals,” p. 211, New York, John Wiley & Sons, 1931.
picture. The prospective teacher of a course in tracer chemistry is given the impression that in order to perform safely the experiments described in this book, the student should be provided with a special laboratory (preferably a separate building) into which he enters through a special chamber where he changes all his clothes, that the student must do all his work in surgical gloves This handbook is a revision and expansion of material which under constant monitoring by survey instruments, that after last appeared as a supplement to the 1945 A.A.T.C.C. Yearbook. finishing he must bathe before returning to his street clothes, New sections on methods of sampling, determination of resins, and that he must have periodic blood examinations. The strict identification of dyestuffs on fibers, and a bibliography oi referregimen laid down by the authors is not followed by the vast ence texts on analytical chemistry have been added. Methods majority of radiochemists because it is unnecessary a t the levels given for analysis of fiber content, and photomicrographs of variof activity normally used. The requirements which the authors ous textile fibers, are those which appeared in the 1946 and 1947have set up are such as thoroughly to discourage anyone con48 yearbooks. templating the teaching of radiochemistry in a university. AlA group of “useful tables and calculations” has been considerthough there is much useful information in the first four chapters, ably enlarged and now contains tables of equivalents for yarn it is virtually impossible to distinguish it without considerable counts and Twaddell-Baum6-specific gravity-percentage conprior knowledge of sound radiochemical laboratory practice, and centration, a tabulation of fatty acid composition and characterthe reviewer therefore suggests that the reader unfamiliar with istics of natural oils, fats and waxes, etc. Additions have been this simply omit the first third of the book. made to the sections on general analytical technique, preparaMost of the remainder of the book is devoted to a collection of tion of standard solutions and reagents, and methods of analysis detailed experiments on the measurement and applications of of chemicals. radioactive tracers. The authors have made an intelligent selecAnalytical methods selected for this compilation have b c w tion, on the whole, of the 28 experiments which illustrate the chosen for their utility in a textile mill laboratory. The book tracer principle as applied to chemistry, physics, and biology. constitutes an excellent addition to the textile laboratory and Each experiment includes a brief theoretical discussion, a list of should be very useful to the textile chemists and students. Unapparatus and materials, a detailed procedure, and questions to fortunately, the index omits specific entries for topics in the secaid in writing the report. At the end of each section there is tions on determination of finishing materials, resins, dyestuffs, appended a list of “other suggested experiments,” but these sugand fiber content. Paper and hinding are serviceable. gestions are usually so general as to be of little practical value. MILTONHARRIS Many of the experiments are, in principle, excellent and should prove stimulating to the student. They have evidently proved satisfactory in the authors’ teaching experience and do not demand unusual facilities or equipment. The directions are as a Radioactive Tracer Techniques. Geo. K . Schweitzer and Ira B. rule clear and detailed. There are occasional rather serious omisWhitney. vi 241 pages. D. Van Nostrand Co., 250 sions, an example of which is the absence of any description of Fourth Ave., Kew York 10, N. Y., 1949. Price, $3.25. or specifications for the standard sample holder or mounting card, although there are frequent explicit references to the use of This book is a laboratory manual designed for use in college both. Although the experiments are in general well chosen, courses on the applications of radiochemistry. A manual of exthere are occasional lapses, as in the illustration of radiometric periments for instructional purposes has been badly needed for analysis by isotope dilution. Here the student is asked to a number of years, and the authors are to be congratulated on evaporate 10- to 50-mg. samples of iron in an ether solution onto having gathered together and made available with specific diwatch glasses for evaporation and weighing as a precise method of rections a wide variety of experiments illustrating most of the determining iron. The intelligent student will immediately major applications of the tracer method, However, the book as realize that there are a number of ways of determining small a whole falls considerably short of being satisfactory. quantities of iron with ten times the accuracy in half the time, and The first third of the book is devoted to a discussion of radioan experiment like this is hardly likely to convince him that the active hazards and the design and functioning of the radiochemitracer method is any boon to analytical chemistry. cal laboratory. The authors have failed, however, to draw a These deficiencies are not so serious, however, as the authors’ distinction between the low-level academic tracer laboratories failure to give a clear and sound explanation of the basic prinRnd high-level industrial laboratories. The result is a distorted
Analytical Methods for a Textile Laboratory, 1949. Americarc Association of Textile Chemists and Colorists, Committee on Analytical Methods for a Textile Laboratory, compilers. v 287 pages. Association of Textile Chemists and Colorists, Lowell Textile Institute, Lowell, Mass., 1949. Price, $6.
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