J. Chem. Eng. Data 1982, 27, 324-326
324
in other words, that the curve for VE, is relatively insensitive to isentropic variations of pressure. The molar excess volumes of monoether-alkane mixtures, as exemplfied by the recent results for din-butyl ether-nhexane (72),are generally lower than for polyether-alkane mixtures, inditing a closer balance between positive and negative contributions. Previously it was suggested (73)that a weak hydrogen bond is formed between the nonbonded electron pairs of an etheric oxygen atom in one molecule and a hydrogen atom of an cr&ted CH, or CH, group in a second ether molecule and that in a polyether the strong inductive effect of several oxygen atoms weakens the C-H bond and enhances the hydrogen bonding. This pictue is consistent with the relatively high enthalpies of vaporization of polyethers in comparison to their alkane homomorphs and also with the relatively large deviations of polyether-alkane mixtures from Raouit's law (73). I n contradistinction, the inductive effect in monoethers is quite weak. Their enthalpies of vaporization are nearly the same as those of their respective alkane homomorphs, and the excess Gibbs energies of monoether-alkane mixtures exhibit only small deviations from ideality (73).The larger molar excess volumes of polyether-alkane mixtures compared to those of monoether-alkane mixtures are also understandableon this basis. However, the present results for VE1and KsElat low x 1 do not show any signs of the behavior whlch characterizesthe results for the alcohol-alkane systems ( 7 4 , 75) where self-association through hydrogen bonding is undoubtedly of importance.
Acknowledgment We are indebted to Mr. P. J. D'Arcy for technical assistance during this investigation.
Glossary 81
C, KsEl KsEm MI
n T U
VE,
coefficient in either eq 4 or eq 7 moiar heat capacity of pure component iat constant pressure, J K-' mol-' partial molar excess isentropic compressibility of component iin mixture, cm3 mol-' GPa-l molar quantity related to the isentropic compressibility by eq 6 molar mass of component i number of coefficients in either eq 4 or eq 7 thermodynamic temperature, K speed of ultrasound, m s-l partial molar excess volume of component iin mixture, cm3 mo1-l
V'/ VEm XE
x/
molar volume of pure component i , cm3 md-l molar excess volume, cm3 mol-' typical excess thermodynamic function mole fraction of component i
ljreek Letters
a*/ E:: K~ ld K~ '/
P' d
6,
isobaric thermal expansivity of pure component i , kK-l isentropic compressibility, TPa-l excess isentropic compressibility, TPa-' isentropic compressibility of corresponding ideal mixture isentropic compressibllity of pure component i , TPa-l density of pure component, g ~ m - ~ standard deviation for least-squares fit volume fraction of i , in terms of the unmixed components
Subscripts 1 2
component 1, trioxanonane component 2, n-heptane
Literature CRed (1) Meyer, R.; Glusti G.; Vincent, E.J.; Meyer, M. Thennochlm. Acta 1977, 19, 153. (2) Treszczanowlcz, T. Untverslly of Ottawa, Ottawa, Canada, prhrate communlcetkm, 1980. (3) RMdlck, J. A., Bunger, W. 8. "Organlc Solvents", 3rd ed.; Wdssberger, A., Ed.; Wky-Intersdence: New York, 1970 Vd. 11. (4) "Selected Values of Propertles of Hydrocarbons and Related Compounds"; American Petrdeum Institute Research Project 44, Thermodynamics Research Center, Texas A & M UntverslW: Cokae Station, ix. (5) Tanaka. R. Klyohara, 0.;D'Arcy, P. J.; Benson. G. C. Can. J . Chem. 1975, 53, 2262. (8) Klyohara, 0.; &oiler, J.-P. E.; Benson. 0. C. Can. J . Chem. 1974, 52. 2207. .-, ~~. (7) Klyohara, 0.; Helpin, C. J.; Benson, 0. C. Can. J . Chem. 1977, 55, 3544. (8) Kroebei, W.; Mahrt, K.-H. AcwHce 1976, 35, 154. (9) Benson, 0. C.; Klyohara, 0. J . Chem. T t " o @ f n . 1979, I f , 1061. (10) Fortier, J . I . ; Benson, G. C.; Picker, P. J . Chem. Thennodyn. 1976, 8 . 289. (11) Bllnowska. A.; Brostow, W. J . Chem. Thermodyn. 1975, 7 , 787. (12) Marsh, K. N.; Ott, J. B.; Costlgan, M. J. J . Chem. Thermcdyn. 1980. 12, 857. (13) Treszczanowlcz, T. Bull. Aced. Pol. Scl., Ser. Scl. Chlm. 1975, 2 3 , 161. (14) Treszczanowicz, A. J.; Benson, G. C. J . Chem. Thermodyn. 1978, 10, 967. (15) Klyohara, 0.;Benson, 0.C. J . Chem. Thermodyn. 1979, I f . 861. Recetved for revlew September 22, 1981. Accepted April 5, 1982.
Sotubltity of Gases in Liquids. 14. Bunsen Coefficients for Several Fluorine-Containing Gases (Freons) Dissolved in Water at 298.15 K Tracy Park, Tknothy R. Rettich, RuMn Battho," Dennis Peterson, and Emmerich WHheimt Department of Chemistry, Wright State University, Dayton, Ohio 45435 Bunsen coemdentr of slx Freon gases, of M u r hexafktoride, end of argon dkS0hr.d In water were at 288'15 K' Two modlfkaUoM Os Scho'ander's mlcroga$ometrlc apparatus were used, and detalls of a new Improved v . n k n are given. t v k m ~seoctateprofessor of "istry born lnstBut Chemie. Unhrerslt&t Wlen, A-1090 Wen. Austrla.
~ y s ~ a l i s c
0021-9568/82/1727-0324$01.25/0
Introduction Despite continued concern about the effects of Freon gases on the environment, few reliable data exist concerning the solubility of these substances in water. The main reason for the paucity of data is the exceedingly small solubility of Freons in water. Yet accurate solubility values need to be known for ~ appropriate modeling and calculation of the longterm fate of Freons. Accordingly, the Bunsen coefficients a of Freon-11 0 1982 American Chemical Society
Joumel of Ctwmlcal and Engkwing Date, Vd. 27, No. 3, 1982 325
Table I. Bunsen Coefficient (a)at 298.15 K for Six Freons, Sulfur Hexafluoride, and Argon Dissolved in Watef
a
Freon-1 1 (CC1,F) exptl Freon-12 (CCJF,) exptl Freon-13 lit: (2) (CClF,)
Flguro 1. Schematic presemtation of the new modified Schdander “gasomtric apparatus. For details see text.
(CCi,F). Freon-12 (CCi2F2),Freon-13 (CCIF,), Freon-14 (CF,), Freon-116 (CRe), Freon4318 (CC,F,), and sulfur hexahride dissolved in pure water at 298.15 K were measured at a total pressure of about 100 kPa. Two modiflcatbns of Scholander’s microgasometric apparatus ( 1 ) were used in the experiment. The value of cy for argon in water was also measured as a check on the modifications. The results of Parmelee (2),though of poor precislon, are the only available data for Freon-12 and Freon-13 in water. Reliable measurements concerning Freon-14 and sulfur hexafluoride are due to Ashton et el. (3).More recently, Freon-14 was included in a study by Wen and MuccIteUi ( 4 ) , which also contains the only available data for Freon-116 and Freon4318 in water. The Bunsen coefficient for argon h water was taken from a review by w#hehn et ai. (5). No solubDlty data could be found for Freon-11 in water.
Matwlal8 Freon-11 (99.9 mol % minimum purity), Freon-12 (99.0%), Freon-13 (99.0%), Freon-116 (99.6%), and SF, (99.9%) were supplied by the Matheson Gas Co. Freon-14 (99.7%) was from Air Products. Freon42318 (99.9%) was from Union Carbkle. Argon (99.998%) was from Abco, Inc. Freon-11 is a liquid at room temperature. A vapor sample was obtalned by placing some Freon-11 in an exhausthrely purged vessel, warming in hot water, and then samplhg via a syrlnge through a side arm. The water used was house “distilled” (reverse osmosis) water, which was passed through ion-exchange columns until its specific resistance was 5 X loe Q cm or better. Apparatus Two different versions of the Scholander microgasometric apparatus were housed in an air bath with temperature controlled to better than f0.05 K. The main advantage of the ab bath over a water bath (as used in previous studies involving a modified Scholander apparatus) is that the ak bath accommodates the entire microgasometrk apparatus, including the micrMeter buret and the mercury reservoir. The first version used was the scholender apparatus as modiRed by Stem (6), Douglas (7),and Rnely Weiss (8). The procedue for degasdw the distilled water, storlng It, and transferring It to the microgasometric apparatus was described by Douglas ( 7 ) . as was the procedure for calculatbn of the Bunsen coefficient. The second version Is depicted In Figure 1. The deslgn includes a more effident method of degasslng and transtenjng
exptl lit. (2) Freon-14 (CF,) exptl lit. (3) lit. (4) Freon-1 16 (C,F,) exptl lit. (4) Freon42318 (cC,F,) exptl lit. (4) SF, exptl lit. (3) argon exptl exptl lit. (5)
SD
0.249 1
1.7
0.065 72 0.05 1
1.0
0.01 7 7 1 0.02
1.7
0.004 75 1 0.004 738 0.004 62
2.1
0.001 206 0.001 26
6.4
0.002 689 0.002 65
1.9
0.005 440 0.005 451
1.3
0.031 22 0.031 05 0.031 21
1.6 0.8
no. of measurements
For each set of measurements the standard deviation is given
in percent, Le., SD = lOOo/c(. water to the microgasometric apparatus. Shown in Figure 1 are a 4mL compensation chamber (A), a 10-mL equilibration chamber (B), and an 8-mL slde arm (C). The groundglassjoint above A Is inverted relative to Schdander’s original design, in order to prevent grease from contaminating A and the rest of the system. H i g h - v a m Rotaflow valves a and b open to the atmosphere and an O-ring joint, respectively. Via this O-ring joint the microgasometric apparatus is connected to the degassing flask (D). Valves c-e are Rotaflow valves used to control the degmlng and transfer of water, and f Is a three-way glass stopcoclc for transferring mercury. Because of the greater a “ t of mercvy requlred by the new design, a larger mercury reservok (H) Is used. The micrometer buret portion (M)of the apparatus remains unchanged from the original design. The procedure for degassing and transferring distilled water in the new design Is as follows. With no water in the system the mercury level is lowered to f, which is then closed along with a, d, and e. The entke system up to valve f is then evacuated, f is opened, and the mercury is allowed to rise to just above valve c, whlch Is then closed. Water is then added to D and degassed by the method of Battino et ai. (9). Valve f is opened to the mercury reservoir and c is opened, allowing the water to flow into C. Valves b and c are closed, and the entire apparatus Is removed from the vacuum line. The mercury is removed from A by opening a until the mercury level fails to the top of the capillary tubing between A and 6. The excess mercury is removed and A is half-filled with distilled water. The microgasometric apparatus is then transferred to the air bath and the gas sample is introduced by the method desalbed by Douglas (7). The cap for A Is replaced, and, after the temperature stabilizes, the procedure of Douglas (7) is subsequently followed. with elther version 30 min to 2 h was required to reach equilibrium conditions. Results and Dlscwrlon
Values of the experimental Bunsen coefficients at 298.15 K are shown in Table I, along with literature values for compar-
326
J. Chem. Eng. Dei% 1982, 27,326-328
ison. ExpwhWai results whlch were obtabred with the newly designed apparatus are italicized. The srenitfcantly larger uncertainty of the results for Freon-116 is a consequence of its extremely small sodubi#ty, which Is close to the llmlt of the apparatus. No significant difference was observed in the precision or
accuacyofthetesu#s obtahedbythetwo methode. However, the new verskn has several advantages over the Douglas version. The main advantage is that degassed water is transferred tothe he dde ann of the "eMcapparatus without the use of an intermediate transfer vessel or syringe. The rlsk of " h a t l o n by air Is thereby practically excluded. The new method a b alkws continuous monitoring of the de~essingprocess. Fkraly, the hi#wacuwn Ratefbw valve seals off the degassed water in the side arm from atmospheric
contamination better than the Teflon plug wed In the Douglas system. Literature Cited (1) S O h d e W , P. F. J . Bkl. Chem. 1947, 167, 235. (2) Parmdee, H. M. Ret?&. €ng. 1919, 6 1 , 1341. (3) AsMon, J. T.; Dawe, R. A.; Mllkr, K. W.; Smlth, E. B.; Sttcklngs, B. J. J . Chem. Soc. A 1 0 0 . 1793. (4) Wen, W.-Y.; MucclW, J. A. J . soknkn Chem. 1979, 8, 225. (5) wl)lekn, E.; httlno, R.; wucock, R. J. chem.Rev. 1977, 77, 219. (8) Stem, H. M .Ooeenqr. l@M, 3, 423. (7) DOUgb, E. J . #rvs. chem.1084, 68. 169. (8) Wdrs, R. F. J . Chem. Eng. l k b p 1971, 16, 235. (9) Bettho, R.; Bo@nI, M.; Bsnzhof, M.; wlhehn, E. Anal. Chem. 1971, 43, 808.
FlwMved for revkw SepMnbw 30, 1981. Acoeptsd Mer& 8, 1982. We acknowkdgs the partlel wppor! of thls work vla NIH grant QMS 14710-12.
V tes and Derrsitlgs at 298.15 K for Mixtures of Methanol, Ac~tone,and Water KatsujJNoda,' MRsuhlsa Ohashl, and Klyoharu I&Ma Deparhent of chemlcel Engbmedng, Shlzuoka Unlverstty, M a m m t s u 432, &pan Table I. Physical Constants of Pure Compounds at 298.15 K viscosity, mPa s density, kg m-'
Introduotkn The viscodtles of Uqukl mixtwes are requked for many practical proMems cor)cBmhaheat traneport, mass transport, and &tkl tkw. Many vkcosHycurves are not aiways simple hrnotkns of the COmpOSltlOns. The devletkm from ideellty is especially large for the systems including hydrogen bonds. I n this study,the viscosities and the densities at 298.15 K are determined for the binary methanokcetone, acetonewater, and water-melhand systems and for the ternary methand-ecetme-water system. The viscosities of the binary systems are conelated by using the McAhter equation of the fou-body Interactions ( 1 ) . This equation b expanded to the temary system and used to correlate the data. Expdmontd Soctlon
Vboodties and densities were measured with an Ostwaib type vi"m and a l 0 - d pycnometer, respectively. These arecalhratedbywhgdeknbeddletlsdwater. Thisequlpment was Immersed in a water bath at 298.15 f 0.05 K. The estimated u m w t a h h in these " m t s are f0.002 pm2 s-' in viscoSltles and *0.2 kg m4 in dendtles. Methanol and acstoneusedh Wsecperimentwasctnrnatogredeream pvchesedtromw~chemlcals,Japen. Asthephysical propertkg for the pure Hqu#s llsted in Table I are consistent wlth wrlues ln the literature within the experknentai error,them chemicals were used without further purifications.
methanol
acetone
0.542 (this work) 0.541 (3) 0.5445 (4) 786.7 (this work) 786.9 (3) 786.64(4) 786.53 (5)
0.301 (this work) 0.302 (2) 0.304 ( 4 ) 784.7 (this work) 784.3 (2) 784.4 (4) 785.01 (5)
Table 11. Viscosity and Density Data for the Binary Systemsat 298.15 K x,
viscosity, pmz s-'
density, kgm-'
0.0 0.1219 0.2100 0.2292 0.2781 0.2939 0.2977 0.3077
0.384 0.4 15 0.413 0.418 0.419 0.421 0.418 0.420
Methanol (1) 784.7 786.3 787.2 787.5 788.0 788.0 787.9 788.4
0.0 0.0507 0.1125 0.1411 0.2276 0.2927 0.4198
0.893 1.126 1.385 1.480 1.657 1.683 1.593
0.0583 0.1460 0.2056 0.3020 0.4597
1.239 1.454 1.393 1.211 0.86 9
x,
viscosity, pmz s-'
density, kgm-3
+ Acetone 0.3551 0.4628 0.6406 0.7026 0.7901 0.8780 1.0
Methanol (1) + Water 997.1 0.4856 983.4 0.5542 966.9 0.7133 960.2 0.8040 941.1 0.8345 925.7 0.9140 898.4 Acetone (1) + Water 974.2 0.5266 943.9 0.6181 925.0 0.7699 897.8 0.8195 861.4
0.431 0.440 0.477 0.499 0.535 0.589 0.689
788.6 789.7 790.5 790.5 790.1 789.4 786.7
1.505 1.396 1.149 0.992 0.952 0.825
884.5 869.9 837.7 821.0 816.0 800.1
0.764 0.613 0.489 0.474
848.1 832.1 810.1 804.0
R e s u b and Dlscudon
Experknentai vkcosities and cknsltles for the binary and ternary liquid mixtures are presented in Tables I 1 and 111. 0021-9568/82/1727-0326$01.25/0
Several empHcel and SemiempHcat relations have been used to represent the dependence of the viscosities on the compo@ 1982 Amerlcan Chemical Society
