IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Ethanol with Benzene and Water

Components:
   (1) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail
   (2) Benzene; C6H6; [71-43-2]  NIST Chemistry WebBook for detail
   (3) Ethanol (ethyl alcohol); C2H6O; [64-17-5]  NIST Chemistry WebBook for detail

Evaluator:
   A. Skrzecz, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland (1997.05)

Critical Evaluation:

      A survey of reported compositions along the saturation curve and compositions of coexisting phases in equilibrium (eq.) and distribution of ethanol between phases (distr.) for the system ethanol-benzene-water is given in Table 17.

Saturation curve
The ternary system ethanol-benzene-water forms a miscibility gap of type 1. Data for the system were reported in 23 references over the temperature range 263-342 K. The system is evaluated on the basis of the original papers. Only one binary system, benzene-water, is partially miscible. The data for this system were compiled and critically evaluated in a previously published SDS volume, Ref. 24. These recommended values of mutual solubility at 293 K are x'₂=0.00975; x"₂=0.000 406; at 298 K– x'₂=0.9970, x"₂=0.000 409 and at 333 K–x'₂=0.991 04, x"₂=0.000 534. Only the paper of Barbaudy, Ref. 9 at 333.2 K reported mutual solubility of the binary system: x'₂=0.9893 and x"₂=0.0005. This is in agreement with the recommended values, Ref. 24. The results of Taylor,¹ Lincon,² Perrakis,⁷ Tarasenkov and Polozhentseva,¹³ and Letcher et al.²³ aare not reported as compilation tables. The data of Taylor¹ and Lincon² at 298.2 K published at 1896 and 1899 were reported as volume ratios. These data were recalculated to mole fractions, and they were taken into account for this evaluation; they are in agreement with other data sets at the same temperature. Data of Perrakis⁷ at 294 K present a significantly larger miscibility gap than any other data at 293 K and therefore these data are rejected as are other alcohol-benzene-water systems presented in Ref. 7. Data of Tarsenkov and Polozhentseva¹³ were obtained for this evaluation from Tarasenkov and Paulsen.²⁵ These data present a much smaller miscibility gap (at maximum ethanol concentration of about 0.03 mole fraction of C₂H₅OH) which is inconsistent with all other experimental data and an unreasonable large solubility of waer in benzene (solubility of benzene in water estimated on the basis of these data seems to reach value x"₂=0.94). Therefore, this data set is rejected. All experimental data of Letcher et al.²³ were presented in the paper in graphical form only and therefore were not compiled. The miscibility gap decreased with the increasing temperature. This behavior is observed in all studies at more than one temperature.^{5,6,9,17,19,22} Data reported by Brandani et al.²² show a slightly smaller miscibility gap than other data at 303.2 K (Wehmann, Ref. 6 and Sata and Kimura, Ref. 14) and at 313.2 K (Morachevskii and Belousov, Ref. 19). The reported data are consistent within each data set and for each study. All data on the saturation curve are treated as tentative. Characteristic points on the binodal curve at selected temperatures, reported or estimated for plait points and for maximum ethanol concentration, are presented in Table 18. At the point of maximum ethanol concentration the errors estimated by the evaluator are 0.005 and 0.015 mole fraction for ethanol and benzene, respectively.
The temperature of 298.2 K, a standard temperature in which various alcohol-hydrocarbon-water systems are presented, was chosen to present the behavior of the system. Saturation and equilibrium data of Refs. 1, 2, 5, 8, 9, 15, 16, and 18, water-rich and hydrocarbon-rich branches were descrbed together by the equation: x₁=0.541 21+0.062 76 ln(x₂)–0.083 61x₂–0.468 57x²₂. The least-squares method was used and the standard error estimate was 0.0106. The proposed equation is not appropriate for the binodal curve at >0.98 mole fraction of benzene. The compositions on the saturation curve calculated by the proposed equation are presented in Table 19 for selected concentrations of benzene in the mixture. The results of the calculations (solid line) are also presented graphically in Figure 10 together with selected experimental data, Refs. 5, 8, 9, 15, 16, 18, reported at 298.2 K.

Phases in equilibrium Compositions of coexisting phases in equilibrium for the ternary system ethanol-benzene-water were reported in 11 references over the temperature range 293-342 K as 20 data sets (mainly isotherms). The tie lines cover the full area of miscibility gap. Reported data are consistent within each data set. Only data of Tarasenkov and Polozhentseva¹³ were rejected; these tie lines were inconsistent with all others. Vapor-liquid-liquid equilibria or boiling points of two-phase mixtures are reported in the papers of Barbaudy¹¹ at 101 kPa and of Morachevskii and Belousov¹⁹ at temperatures 308.2, 318.2, 328.2, and 337.2 K. These data sets are consistent with other equilibrium data at lower temperatures. Changes of tie line direction are observed with temperature. With increasing temperature the water concentration in benzene-poor phase decreases for similar composition of benzene-rich phase; at temperatures over 333 K the concentration (in mole fraction) of ethanol in both phases in equilibrium reaches nearly the same values. This may be observed in data sets reported in Refs. 9, 11, 19, and 22. The equilibrium compositions of both phases of Ross and Patterson at 293.2 K²¹ (referring also to density and surface tension of phases in equilibrium), are identical with those of Morachevskii and Belousov.¹⁹ The reported experimental plait points are presented in Table 17. All equilibrium data are treated as tentative. Selected experimental points at 298.2 K, both saturation and equilibrium data, are presented in Figure 10 .

Experimental Data: (Notes on the Nomenclature)

TABLE 17. Summary of experimental data for the system ethanol-benzene-water
Author	T/K	DataType	Reference
Taylor, 1896	298	sat. (14), eq. (6)	1
Lincoln, 1899	298	sat. (13)	2
Bonner, 1909	288	sat. (12)	3
Holmes, 1918	288	sat. (1)	4
Sidgwick and Spurrell, 1920	273-298	sat. (32)	5
Wehrman, 1921	263-303	sat. (33)	6
Perrakis, 1925	294	sat. (11)	7
Barbaudy, 1926	298	sat. (9)	8
Barbaudy, 1926	298-338	sat. (26), eq. (13)	9
Wright, 1926	284-296	sat. (7)	10
Barbaudy, 1927	338-342	eq. (6)	11
Washburn et al. 1931	298	sat. (16), distr. (9)	12
Tarasenkov and Polozhentseva, 1932	293	eq. (6)	13
Sata and Kimura, 1935	303	sat. (7)	14
Varteressian and Fenske, 1936	298	sat. (10), eq. (14)	15
Bancroft and Hubard, 1942	298	sat. (4), eq. (12)	16
Staveley et al., 1951	274-342	sat. (45)	17
Chang and Moulton, 1953	298	sat. (12), eq. (11)	18
Morachevskii and Belousov, 1958	293-337	eq. (35)	19
Mertslin et al. 1961	299	sat. (20), distr. (12)	20
Ross and Patterson, 1979	293	eq. (9)	21
Brandani et al. 1985	303-328	eq. (34)	22
Letcher et al. 1990	298	sat. (13), eq. (5)	23

TABLE 18. Characteristic points on the binodal curve of the system ethanol-benzene-water
T/K	Mole Fraction x₁	Mole Fraction x₂	Comment(s)
288.2	0.438 Ref. 3	0.198 Ref. 3	Max. C2H5OH concentration
288.2	0.389 Ref. 3	0.413 Ref. 3	Plait points
293.2	0.435 Ref. 6	0.195 Ref. 6	Max. C2H5OH concentration
293.2	-	-	Plait points
298.2	0.418 Ref. 16	0.211 Ref. 16	Max. C2H5OH concentration
298.2	0.391 Ref. 9	0.318 Ref. 9	Plait points
298.2	0.416 Ref. 15	0.181 Ref. 15	Max. C2H5OH concentration
298.2	0.393 Ref. 15	0.322 Ref. 15	Plait points
298.2	0.419 Ref. 18	0.244 Ref. 18	Max. C2H5OH concentration
298.2	0.398 Ref. 18	0.325 Ref. 18	Plait points
298.2	0.40 Ref. 23	0.20 Ref. 23	Max. C2H5OH concentration
298.2	0.38 Ref. 23	0.37 Ref. 23	Plait points
299.2	0.425 Ref. 20	0.262 Ref. 20	Max. C2H5OH concentration
299.2	0.395 Ref. 20	0.343 Ref. 20	Plait points
303.2	0.385 Ref. 22	0.154 Ref. 22	Max. C2H5OH concentration
303.2	0.365 Ref. 22	0.353 Ref. 22	Plait points
303.2	0.412 Ref. 6	0.226 Ref. 6	Max. C2H5OH concentration
303.2	-	-	Plait points
313.2	0.384 Ref. 19	0.198 Ref. 19	Max. C2H5OH concentration
313.2	0.344 Ref. 22	0.330 Ref. 22	Plait points
328.2	0.354 Ref. 22	0.271 Ref. 22	Max. C2H5OH concentration
328.2	0.354 Ref. 22	0.271 Ref. 22	Plait points
338.2	0.344 Ref. 9	0.212 Ref. 9	Max. C2H5OH concentration
338.2	0.344 Ref. 9	0.212 Ref. 9	Plait points

TABLE 19. Calculated compositions along the saturation curve at 298.2 K
T/K	Mole Fraction x₁	Mole Fraction x₂
298.2	0.0000	0.000 409 Ref. 24
298.2	0.1076	0.0010
298.2	0.2513	0.0100
298.2	0.2938	0.0200
298.2	0.3351	0.0400
298.2	0.3579	0.0600
298.2	0.3730	0.0800
298.2	0.3837	0.1000
298.2	0.3914	0.1200
298.2	0.3969	0.1400
298.2	0.4008	0.1600
298.2	0.4034	0.1800
298.2	0.4047	0.2000
298.2	0.4051	0.2200
298.2	0.4046	0.2400
298.2	0.4033	0.2600
298.2	0.4012	0.2800
298.2	0.3984	0.3000
298.2	0.3950	0.3200
298.2	0.3909	0.3400
298.2	0.3863	0.3600
298.2	0.3811	0.3800
298.2	0.3753	0.4000
298.2	0.3690	0.4200
298.2	0.3622	0.4400
298.2	0.3549	0.4600
298.2	0.3471	0.4800
298.2	0.3388	0.5000
298.2	0.3300	0.5200
298.2	0.3208	0.5400
298.2	0.3111	0.5600
298.2	0.3009	0.5800
298.2	0.2903	0.6000
298.2	0.2793	0.6200
298.2	0.2678	0.6400
298.2	0.2558	0.6600
298.2	0.2435	0.6800
298.2	0.2307	0.7000
298.2	0.2175	0.7200
298.2	0.2039	0.7400
298.2	0.1898	0.7600
298.2	0.1753	0.7800
298.2	0.1604	0.8000
298.2	0.1451	0.8200
298.2	0.1294	0.8400
298.2	0.1133	0.8600
298.2	0.0967	0.8800
298.2	0.0798	0.9000
298.2	0.0625	0.9200
298.2	0.0447	0.9400
298.2	0.0265	0.9600
298.2	0.0080	0.9800
298.2	0.0000	0.9970 Ref. 24

View Figure 1 for this Evaluation

Notes:
Table 17  Number of experimental points in parentheses.

References: (Click a link to see its experimental data associated with the reference)

   1  Taylor, S.F., J. Phys. Chem. 1, 461 (1896-1897).
   2  Lincoln, A.T., J. Phys. Chem. 4, 161 (1899-1900).
   3  Bonner, W.D., J. Phys. Chem. 14, 738 (1909-1910).
   4  Holmes, J., J. Chem. Soc. 113, 263 (1918).
   5  Sidgwick, N.V., Spurrell, W.J., J. Chem. Soc. 117, 1397 (1920).
   6  Wehrmann, F., Z. Elektrochem. 27, 379 (1921).
   7  Perrakis, N., J. Chim. Phys. 22, 280 (1925).
   8  Barbaudy, J., Bull. Soc. Chim. Fr. 39, 371 (1926).
   9  Barbaudy, J., Recl. Trav. Chim. Pays-Bas Belg. 45, 207 (1926).
   10  Wright, R., J. Chem. Soc. 129, 1203 (1926).
   11  Barbaudy, J., J. Chim. Phys. 24, 1 (1927).
   12  Washburn, E.R., Hnizda, V.; Vold, R., J. Am. Chem. Soc. 53, 3237 (1931).
   13  Tarasenkov, D.N.; Polozhentseva, E.N., Zh. Obshch. Khim. 2, 84 (1932).
   14  Sata, N.; Kimura, O., Bull. Chem. Soc. Jpn. 10, 409-20 (1935).
   15  Varteressian, K.A.; Fenske, M.R., Ind. Eng. Chem. 28, 928 (1936).
   17  Staveley, L.A.K.; Johns, R.G.S.; Moore, B.C., J. Chem. Soc. 1951, 2516-23.
   18  Chang, Y.C.; Moulton, R.W., Ind. Eng. Chem. 45, 2350 (1953).
   19  Morachevski, A.G.; Belousov, V.P., Vestn. Leningr. Univ., Ser. 4: Fiz., 4, 117 (1958).
   20  Mertslin, R.V.; Nikurashina, N.I.; Kamaevskaya, L.A., Zh. Fiz. Khim. 35, 2628 (1961).
   21  Ross,S.; Patterson, R.E., J. Chem. Eng. Data. 24, 111 (1979).
   22  Brandani, V.; Chianese, A.; Rossi, M., J. Chem. Eng. Data 30, 27 (1985).
   23  Letcher, T.M.; Sewry, J.; Radloff, S., S. Afr. J. Chem. 43, 56 (1990).
   24  Shaw, D.G., ed., Solubility Data Series, Vol. 37, Hydrocarbons with Water and Seawater, Part I: Hydrocarbons C5 to C7 (Pergamon, New York, 1989).
   25  Tarasenkov, D.N.; Paulsen, I.A., Acta Physicochim. URSS 11, 75 (1939).