V O L U M E 23, N O , 9, S E P T E M B E R 1 9 5 1 acids (4). The diversity of the compounds anslysed in this work with no rccovcries below 96% of theory demonstrates that thc regular Kjeldahl microprocedure, with the nddition oi tho sealed-tube hydrolysis for acrylonitrile, is entirely satisfactory for many nitrilcs and suggests t h a t it is probably generally applicable.
139 LITERATURE CITED
X. P., "Semimicro Quantitative
Organic Analysis," p. 37, New York, Academic Press, 1943. F..Ind. Eng. Chon., 37, 482
(1) Clark,
(2) Davis, H. S., stid Wiedeman, 0. 1194.51.
ACKNOWLEDGMENT
The authors express their thanks to L. L. McKinney and F. H. Stodola for the generous samples of most of the compounds used
211 (1945). (7) Willits, C. O., Coe, M. R..and Ogg, C. L.. .I. Assoc. O&. Chaists.32.118 (1949). . . .
in this study.
REOE~E Deoember4.1950 D
Aqr.
48. Tetrachlorophthalic Anhydride Contributed by W. C. MCCRONE, Armour Researoh Foundation of Illinois Institute of Technology, Chicago 16, Ill.
0
CI
I
//
C
C
CI-C -
L\\ c
/I
\ 0
,,c;\C/
I
CI hydride may hydrolyze to the acid water; hence this solvent should not he used. Ether and benzene are satkfactory, although by ie the bcst crystals for analytical purposes are obtained by slow sublimation in a Kofleer block a t about 150" C. (Figure 1, A ) . Below 150' C. long rods and needles are formed; above 150" C. more massive crystals can he iormed. l h e latter method of preparing crystals is particularly good in this case bccaurc m y beid present is converted by sublimation t o the anhydride. A very unstable polymorphic farm is sometimes obtained from the melt (me hclow). ~
LcbLJoyL2LiyL"LLyy
llylll
CRYSTAL MORPHoi.oGY Crystal System. Monoclinic. ' Form and Habit. From sublimation stubby and long rods elongated parallel to hL The orthopinacaid I I O O ] and the positive hemiort,hodome [ 101 1 closcd by eit.hcr the clinopinscaid or
Figure 2. Orthographic Projection of Typical Crystal or Tetrachlorophthalio Anhydride the positive hemipyramid (1111. The hemiorthodome (2011 and the basal pinamid 1001 are also common. AxialPatin. a : b : c = 3.104:1:2.11_6. Interfacial Angles (Pol:~r). 100 A 101 = 91"; 001 A 201 =
lmDRn' -..
Bets. Anglc.
132". Princioal Lines
d
6.10 4.5h
4.17 3.57 3.40 3.32 3.11 2.99 2.89 2.80 2.75 2.60 2.59 2.43 2.36 2.27 2.22
.
I/If 0.07 0.13 0.26 0.86 0.12 0.21 0.01 1.00 0.14 0.87 0.93 0.05 0.53 0.10 0.27 0.16 0.32
d 2.12 2.11
2.07 1.93 1.89 1.86 1.79 . 1 .76
1.73
1.68 1.64 1.57 1.46 1.44 I.3R 1.36
I/II 0.31 0.34 0.47 0.43 0.12 0.5 0.2 0.3 0.2 0.1 0.6 0.1 " 7
X-RAYDIFFRACIIOV DATA Cell Dimensions. a = 18.10A.; b = 5.83 A.; c = 12.34A. Formula Krights per Cell. 4 (3.994 x-ray).
ANALYTICAL CHEMISTRY
1340 Formula \\-eight. 285.43. Density. 1.970 (flotation plus pycnometer).
1.973 (x-ray).
OPTICAL PROPERTIES Refractive Indexes (5893 .4,; 250 c,). a = 1,612 & 0.002, @ = 1.737 zk 0.004. y = 1.88 & 0.01. 25' C.). 2V = 87". Optic -4xial Angles. (5893 Dispersion. z' > T . Optic Axial Plane. 010. Sign of Double Refraction. Positive. Acute Bisectrix. 0 1 . Extinction. y I. n = 14" in obtuse p. Molecular Refraction ( R ) (5893 A . ; 25' c.). = 1.740. R(ca1cd.) = 58.4. R(ohsd.) = 54.5.
+&
FCSION D a ~ a . Tet,rachlorophthalic anhydride melts a t 255257" C. with considerable sublimation. Well-formed rods (Figure 1, B ) showing parallel extinction and off-center optic axis figures [2V = 8 7 " ; ( - ) ; (v > T ) ] are common in the subhmate. When completely melted, a n extremely unstable polymorph grows for an instant before a solid-solid transformation occurs; the remaining melt solidifies very quickly. These crystals and those obtained on meltback show the off-center optic axis figure. Characteristic shrinkage cracks are clearly visible (Figure 1, B ) . COSTRIBCTIOSS of crystallographic d a t a for this section should be sent t o Walter C. Alecrone, supervisor, Analytical Section, Armour Research Foundation of the Illinois Institute of Technology, Chicago. Ill.
....
Methods of Vitamin Assay. dssocl'atiori oj' 1 7 f t ( / r r / f j i ( ' h e m i s f s , Zrac. 2nd edition. xviii 301 pages. Interscienc-c:I'ublishws, IIIC.,250 Fifth .%ve.. S e w York 1, S. 1951. I'ricca, $5.50.
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This is a much improved manual for vitanliii analysts-the C', riiavin, and first edition covered oiily vitamins .%, 13,, carotene, whereas the present edition also contains \\-orking directions for measuring vitaniiw B8,131u. folic wid, biotin, and pantothenic acid. -4chapter is devoted to each vitamin and iiicladc~shistorical information aimed to give the reader-analyst a Ii:tc~kgrouridfor appreciating the nutritional and medical importancat> of tho dietary fa($or being described. The test is accurate but exceedingly dry-both virtue and failing probably ducs to thr panic reason, group participation rather than individual action. The chapters tvere authored by various expert committees of the Association of Vitamin Chemists, Inc., and numerous independent authorities served as referees and carcfully corrected the test a t the manuscript stage. Two very valuable chapters deal with the importance and statistics of sampling for vitamin analyses, and ivith the short cuts and common principles and procedures of microbiological assay techniques. The ready availability of check samples (liver, tom:tto juice, enriched flour, and dried yeast) n-as announced in thc first edition in 1947. Analytical experience with these check samples since then has undoubtedly rrsulted in the accumulation of a tremendous amount of valuable data. I t is urifortunate that such data R-ere not collected and an estimate of interlaboratory precision for each of tho vitamin analyew calculatcd and included I'HIL~P I,. HARRIS in this edition. 1 3 7 ,
Methodes d'Analyse des Reactions en Solution. G. Charlot and R. Gaugin. viii 328 pages. Masson et Cie., 120 Boulevard Saint-Germain, Paris t?', France, 1951. Price, 86.50.
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This interesting book describes the principles, methods, and techniques of determining equilibrium and specific rate constants, and of investigating the stoichiometry of chemical reactions in solution. The presentation is original, for the authors attempt t o systematize and extend the many methods developed in recent years for the study of redox and acid-base reactions, complex ion formation and dissociation, and precipitation reactions. ' I n the first part of the book (80 pages) is given an unusually comprehensive and penetrating analysis of the mathematical equations that govern simple and complex reactions and that relate the reaction constants to experimentally measurable quantities such as concentration, pH, and redox potential.
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This is a comprehensive coverage of water treatment. Its thoroughness is made possi1)le by the many years of experience of the author in this field. Kumerous tables and charts present data t o illustrate pertinent points as discussed. Effective use is made of photographs and drawings t o describe units used in various processes. Extensive references are given in the bibliographies at the end of each chapter, adding to the value of the book. An appendix summarizes many useful data not otherwise suitable for inclusion in the text proper. Great attention is given t o a detailed discussion, chapter by chapter, of the various classes of constituents found in natural waters, with emphasis on their effect. Methods of treatment for removal of harmful substances and the addit'ion of desirable components are shown in detail in subsequent chapters. Throughout the book the author has described the newer developments in the field, but without slighting the older "conventional" methods. Also included are brief but adequate procedures for
