son between the molal volumes of n-octane and 2,2,3,3-tetramethylbutane, discussed by Hildebrand before the Faraday S0ciety.l Our figures were obtained by weighing known masses of the solid substances under liquid nitrogen, under methyl alcohol a t the sublimation temperature of C02,and, in the case of the C2(CH3)a,under cold water and under liquid hydrogen. The density of n-CsHls at liquid hydrogen temperature, 0.948, is known through the observations of Heuse.2 Materials.--"Synthetic" n-octane from the Matheson Co. was used without further purification. The C2(CHa), was vacuum distilled from material generously furnished by Dr. G. Calingaert, of purity stated as 99.69%, and melting point 100.69'. Procedure.-Samples were either frozen about a cop er wire or in a heavy copper cup. Each sample was thorougEly degassed in the liquid state, and moisture was carefully excluded. Details can be furnished upon request. The densities of liquid hydrogen and methyl alcohol a t the temperatures used were determined by weighing a 10-g. brass weight immersed therein.
Results are given in Table I.
we calculated the molal volumes of these two octanes plotted' in Fig. 1. It is noteworthy that although the more symmetrical octane occupies a larger volume a t low temperatures, as would be expected by analogy with the relative packing of spheres and rods, the reverse is true with their liquids. There is an interesting parallelism between the volume of C2(CH3)sand its entropy in the same range, from the measurements of Scott, Douslin, Gross, Oliver and Huffman.6 This work was supported in part by the Atomic Energy Commission. (5) D. W. Scott, D. R. Douslin, M. E. Gross, G. D. Oliver and H. M. Huffman, ibid., 74, 883 (1952).
T H E SOLUBILITY OF CHLORINE I N CARBON TETRACHLORIDE BY THORL. SMITH^ Contribution from Experiment Station, HercuEea Powder Company, Wilmington, Delaware Received Aupust SO. 196.4
TABLE I DENSITIES OF n-CsHla AND C ~ ( C H ~ ) B
Theories concerning solubility of non-electrolytes have been developed, primarily, by Hilde- 1 9 5 . 8 0.919,O. 917.0.910 brand2 and associates. To test and develop these - 7 5 . 0 .860, ,855 theories, solubility data are needed of non-electro-252.8 ,932 lytes in various solvents and over wide temperature -195.8 .893, .911, .897,0.903 - 7 3 . 8 .850, ,844 ranges. Some years ago the solubility of chlorine in carFrom these densities and those a t higher temperatures obtained by Timmermans3 for n-CsH18, bon tetrachloride at 0,19 and 40" was measured by and by Seyer, Bennett and Williams4 for C2(CH& Taylor and Hildebrand.3 These data are still used in discussing solution t h e ~ r i e ssince , ~ no additional solubility data have been reported. I In this paper, the solubility of chlorine in carbon tetrachloride from 40 t o 90" is given. It appears that the solubility a t 40" reported by Taylor and I Hildebrand is slightly low. Our results combined with their solubility data show that the solutions Immersing Octane liquid n-CsHia Nn CHIOH Cz(CHa)s Hn Nn CHaOH
t,
Density
'C.
Av. 0.915 ,857 .932 ,901 ,847
.
a -
2l
-0.40 -0.60 $-0.80 3 - 1.00 - 1.20 -
L
aJ
a l
0: 0
J I 2
3
OUR DATA
o DATA OF
.I
AND
n.
r(
-.-I
01
>
I
-1.40
I
I
T. Fig. 1. (1) J. H. Hildebrand, Faraday Society Disc., 16, 9 (1953). (2) W. Heuse, Z. p h y s i k . Chem., 6147, 266 (1930). (3) J. Timmermans, "Pliysico-Chemical Constants for Pure Organir Compounds," Elsevier Pub. Co., Inc., New York, N. Y., 1950, p. 80. C ' ( 4 ) W. F. Seyer, R. B. Bennett and F. C. Williams, J . Am. Chem. S O C . , ~3447 ~ ~ (1949). ,
I 2.60
I
I
I
I
-
2.80 3.00 3.20 3.40 3.60 3.80 I / T x 103. Fig. 1.-Solubility of chlorine in carbon tetrachloride and ethylene bromide. (1) Jet Propulsion Laboratory, California Institrite of Technology, Pasadena, California. (2) ,I. H. Hildebrand and R. L. Scott, "Solubility of Non-electrolytes," Third edition, Reinhold Publ. Carp., New York, N. Y., 1950. (3) Nelson W. Taylor and J. H. Hildebrand, J . Am. Chem. Soc., 46, 682 (1923).
(4) J. Chr. Gjaldbaek and J. H. Hildebrand, ibid., 72, 609 (1950).
NOTES
Feb., 1955 deviate from ideality less than was previously assumed. Also, the solubility curves for chlorine in carbon tetrachloride and in ethylene bromide, shown in Fig. 1, are parallel instead of crossing as shown earlier.4 SOLUBILITY
Temp., OC.
40
OF
TABLE I CHLORINE IN CARBON
TETRdCHLORIDE
Total Moles Clr/ pressure (atm.) (kg. soln.)/(atm. Clz)
NCW Atm. Ch
0.797
2.02 2.36
0.789 Av. 0.793
0.115
50
2.02 2.36
0.590 0.602 Av. 0.596
60
2.02 2.36
0.522 0.522 Av. 0.522
0.0771
70
2.36 2.36
0.417 0.433 Av. 0.425
0.0632
0.340 0.329 Av. 0.335
0.0502
0.0875
~
80
2.36 2.70
90
2.70
0.296
0.0444
Experimental.-The solubilities were determined using a two-bulb glass apparatus with a pressure stopcock and a spherical joint between the upper and lower bulbs. The upper bulb was partially filled with distilled carbon tetrachloride and heated for several minutes in a hot bath (130-140") in order to degas the solvent and sweep the air out of the bulb. A 20% solution of potassium iodide was added to the lower bulb which was then weighed and attached to the upper bulb. The apparatus was connected to a cylinder of chlorine (The Matheson C2mpany) and immersed in a therAfter flushing the connecting mostat regulated to f O . l tubing with chlorine several times, the apparatus was agitated by hand until the total pressure in the system, measured with a calibrated Bourdon gage, remained constant. The stopcock was then turned, allowing a sample of saturated chlorine solution to flow into the potassium iodide solution. The lower bulb was detached and weighed. The amount of iodine liberated by the chlorine was determined by titrating with standard sodium thiosulfate solution using starch solution as the end-point indicator.
189
quently the chlorine-carbon tetrachloride solutions show less deviation from ideality above 40" than predicted by an extrapolation of the earlier data.
EXCHANGE BETWEEN HEAVY WATER AND CLAY MINERALS* BY JOSEPH A. FAUCHER~ A N D HENRY C. THOMAS Deportment 01Chemistry, Y a l e University, New Haven, Conn. Received September BO, 1064
Water associated with a clay mineral may either be an integral part of the crystal lattice, as OH groups, or bound more or less loosely to the clay in a variety of ways. We report here experiments of a somewhat preliminary nature on exchanges between the water of clays and added deuterium oxide done in the hope of adding to our knowledge on the nature of clay water and the intimacy of its contact with the structural hydroxyl groups. The exchange of deuterium oxide directly with the hydroxyl groups of two clay minerals has been studied by McAuliffe, Hall, Dean and Hendricks3 who found with kaolinite and halloysite complete and rapid H-D exchange with surface OH groups and a slow diffusion into the lattice a t elevated temperatures. These workers used clay intensively dried in vacuo. The present work was done with air-dried material, Le., with material containing much free water, and the exchange results correlated with weight-loss curves done a t temperatures up to 800". Experimental
The procedure for most of the exchanges was as follows. About 0.5 g. of clay of known water content was accurately weighed into a small glass centrifuge tube, heavy water added, and the tube again weighed. The tube was tightly closed, shaken vigorously and allowed to stand overnight. After more shaking the tube was centrifuged and the supernatant liquid (about 0.5 g.) removed. The water mixture was distilled in a short-path molecular type still, used merely for ease in handling the small samples, closed to the outer atmosphere through a drying tube. The distillates were analyzed by means of a Zeiss dipping refractometer equipped with the auxiliary prism for small samples. Temperature control for the refractometer was provided by a water-bath at Discussion.-The results of the solubility meas- 30.00 f 0.03'. The instrument was set against water, urements are given in Table I. The total pres- taking n = 1.33196 a t 30". Our stock of 9935% DzOgave sures a t which the measurements were made are a reading corresponding to n = 1.32754 for pure D20. gives 1.32760 for pure DzO a t 30". Compositions given along with chlorine solubilities expressed both Luten4 of mixtures were computed taking the refractive index as a as moles of chlorine/1000 grams of solution/atmos- linear function of mole fractions, according to Luten an esphere chlorine partial pressure and as mole frac- cellent approximation. Two synthetic mixtures of H 2 0 tion of chlorine/atmosphere chlorine partial pres- and D20 gave results within the error of reading the instrument, about 0.00002 in m. This instrumental uncertainty sure. The partial pressures of carbon tetrachlo- entails gross errors in the analysis of mixtures of low H 2 0 ride were calculated from the vapor pressure of car- content, hence our experiments were done with as large a bon tetrachloride5 assuming Raoults law, and the ratio of clay to added DzO as could be conveniently handled. partial pressures of chlorine were obtained by dif- Even so, the determination of small exchanges is subject to large error. ference. Weight loss curves on the minerals were obtained simply Figure 1 shows our solubility data along with the by heating samples in platinum crucibles in a regulated solubility data of Taylor and Hildebrand3 for chlo- muffle furnace for periods of 12-24 hours at each temperarine in carbon tetrachloride and in ethylene bro- ture. Temperatures were measured on a thermocouple mide. Also shown are the ideal solubilities, f/j'J,placed near the crucibles.
.
calculated previously. * It appears that the two solubility lines do not intersect, as previously r e p o r t e ~ l , ~and , ~ conse(5) J. Timinermans, "Pliysico-C1i~111ical Constants of Pure Organic Compounds," Elsevier Publisliirig Co., New York, N. Y., 1950, p. 225.
(1) Contribution No. 1248 from the Sterling Chemistry Laboratory of Yale University, New Haven, Connectiout. (2) 22 Hamilton Place, Garden City, N. Y. (3) C. D. McAuliffe, N. S. Hall, L. A. Dean and S. B. Hendricks, Proc. Soil Sci. Soc. Amer., 12. 119 (1947). (4) D. B. Luten, Phus. Rev.. 45, 11.31 (193.4).
