IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Ethanol with Toluene and Water

Components:
   (1) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail
   (2) Ethanol (ethyl alcohol); C2H6O; [64-17-5]  NIST Chemistry WebBook for detail
   (3) Toluene (methylbenzene); C7H8; [108-88-3]  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 (sat), and compositions of coexisting phases in equilibrium (eq.) and distribution of ethanol between phases (distr.) for the system ethanol-toluene-water is given in Table 25.

Saturation curve The ternary system ethanol-toluene-water forms a miscibility gap of type 1. There are 12 references for this system over the temperature range 243-353 K. This evaluation was made on the basis of original papers with the exception of data of Ormandy and Craven,³ Tarasenkov and Polozhentseva,⁴ and Leikola,⁶ which were taken from the handbook of Kafarov,¹³ these data were also taken into account during evaluation but are not reported as compilation sheet because they do not contribute further to knowledge of the system. Only the binary system toluene-water is partially miscible. The data for this system were compiled and critically evaluated in a previously published SDS volume.¹⁴ The recommended values of mutual solubility at 298 K are x'₂=0.9972 and x"₂=0.000 0104. The papers of Borisova et al.,⁹ (x'₂=0.9976 and x"₂=0.0001 at 293.2 K) and Letcher and Siswana,¹² (x'₂=0.999 and x"₂=0.000 at 298.2 K) report mutual solubility of the binary system. Accuracy of experimental data reported in Ref. 12 was stated by the authors to be 0.005 mole fraction, so these data are consistent. The water-rich phase, Ricna et al.¹¹ is reported to be toluene free over a wide range of temperatures and water concentrations. This indicates that their experimental accuracy was in the range of 0.001-0.005 mole fraction; lower than reported (0.001 mole fraction). Data of Arzhanov et al.⁹ reported for the temperature range 348-347 K describe the vapor-liquid-liquid equilibrium. (The boiling temperatures of two-phase mixture of Ref. 8 were estimated from authors graph.) The point (x₁=0.5536 and x₂=0213) on saturation curve at 278.2 K, Rican et al.¹¹ appears to contain a typing error and is rejected. Data reported for 273.2, 293.2, 313.2 K by Tarasenkov and Polozhentseva⁴ contain errors for the toluene-rich phase; the experimental points are inconsistent with saturation curve in the region of low concentration of ethanol. These data are also rejected. Data of Borisova et al.⁹ at 293.2 K close to the plait point, show a miscibility gap similar to the data at 273 K and larger than data of Leikola.⁶ All other data for the saturation curve are consistent with one another. Ormandy and Craven³ reported seven isotherms which clearly show the temperature dependence of the saturation data in the range 243-303 K. Characteristic points of the binodal curve of the system ethanol-toluene-water at selected temperatures, reported in literature, are presented in Table 26. At the maximum ethanol concentration point, the errors estimated by the evaluator are to be 0.005 and 0.015 mole fraction of ethanol and benzene, respectively.
The temperature of 298.2 K was selected to present the behavior of the system. All experimental saturation and equilibrium points at 298.2 K water-rich and benzene-rich branches together, were described by the equation: x₁=0.718 83+0.092 81 ln(x₂)–0.488 76x₂–0.230 41x²₂. The least-squares method was used and the standard error of estimate was 0.0125. The compositions on the saturation curve calculated by the proposed equation are presented in Table 27 for selected concentrations to toluene in the mixture. The results of calculations (solid line) are also presented graphically in Figure 14 together with all experimental data reported at 298.2 K.

Phases in equilibrium Compositions of the coexisting phases in equilibrium for the ternary system ethanol-toluene-water were reported in six references over the temperature range 273-357 K as 11 data sets. Two of these data sets, of Arzhanov et al.,⁸ and Borisova et al.,⁹ were measured at the boiling temperatures of two-phase mixtures at atomospheric pressure. Data reported by Tarasenkov and Polozhentseva⁴ contain errors in the toluene-rich phase, as discussed above, and are rejected. Equilibrium phases for a boiling point of 248.2 K, Borisova et al,⁹ contain presumably an analytical error. This tie line is inconsistent within the data set; other tie lines at boiling temperatures, Refs. 8 and 9, are consistent and cover the full miscibility gap. Other reported data are consistent within each data set. The distrbution of ethanol (direction of tie lines) between the phases changes with temperature and at the boiling point (348-357 K) the concentration of ethanol in both phases becomes nearly the same. The reported plait points are presented above in Table 2. All equilibrium data are treated as tentative. All experimental points at 298.2 K, both saturation and equilibrium data, ^{3,5,7,10,11,12,} are presented in Figure 14 .

Experimental Data: (Notes on the Nomenclature)

TABLE 25. Summary of experimental data for the system ethanol-toluene-water
Author	T/K	DataType	Reference
Curtis, 1897	273	sat. (7)	1
Bonner, 1909	273	sat. (8)	2
Ormandy and Craven, 1921	243-303	sat. (48)	3
Tarasenkov and Polozhentseva, 1932	273-313	eq. (14)	4
Washburn et al., 1939	298	sat. (17), distr. (9)	5
Leikola, 1940	293	sat. (8)	6
Mondain-Monval and Quiquerez, 1940	298	eq. (8)	7
Arzhanov et al., 1975	348-357	eq. (6)	8
Borisova et al., 1978	293-353	eq. (17)	9
Bevia et al., 1985	298	sat. (10)	10
Ricna et al., 1989	278-323	sat. (7), eq. (37)	11
Letcher and Siswana, 1992	298	sat. (15), eq. (6)	12

TABLE 26. Characteristic points on the binodal curve of the system ethanol-toluene-water
T/K	Mole Fraction x₁	Mole Fraction x₂	Comment(s)
243.2	0.573 Ref. 3	0.168 Ref. 3	Max. C2H5OH concentration
243.2	-	-	Plait points
258.2	0.541 Ref. 3	0.113 Ref. 3	Max. C2H5OH concentration
258.2	-	-	Plait points
273.2	0.523 Ref. 3	0.143 Ref. 3	Max. C2H5OH concentration
273.2	-	-	Plait points
273.2	0.520 Ref. 2	0.128 Ref. 2	Max. C2H5OH concentration
273.2	-	-	Plait points
278.2	0.512 Ref. 3	0.161 Ref. 3	Max. C2H5OH concentration
278.2	-	-	Plait points
278.2	0.505 Ref. 11	0.100 Ref. 11	Max. C2H5OH concentration
278.2	-	-	Plait points
288.2	0.493 Ref. 3	0.193 Ref. 3	Max. C2H5OH concentration
288.2	-	-	Plait points
293.2	0.475 Ref. 6	0.166 Ref. 6	Max. C2H5OH concentration
293.2	-	-	Plait points
293.2	0.503 Ref. 9	0.197 Ref. 9	Max. C2H5OH concentration
293.2	0.464 Ref. 9	0.357 Ref. 9	Plait points
298.2	0.474 Ref. 3	0.123 Ref. 3	Max. C2H5OH concentration
298.2	0.423 Ref. 7	0.341 Ref. 7	Plait points
298.2	0.473 Ref. 11	0.127 Ref. 11	Max. C2H5OH concentration
298.2	-	-	Plait points
298.2	0.472 Ref. 12	0.159 Ref. 12	Max. C2H5OH concentration
298.2	0.41 Ref. 12	0.36 Ref. 12	Plait points
303.2	0.465 Ref. 3	0.139 Ref. 3	Max. C2H5OH concentration
303.2	-	-	Plait points
323.2	0.425 Ref. 11	0.160 Ref. 11	Max. C2H5OH concentration
323.2	-	-	Plait points
347.6	0.415 Ref. 9	0.166 Ref. 9	Max. C2H5OH concentration
347.6	0.403 Ref. 9	0.228 Ref. 9	Plait points
347.7	-	-	Max. C2H5OH concentration
347.7	0.342 Ref. 8	0.219 Ref. 8	Plait points

TABLE 27. Calculated compositions along the saturation curve at 298.2 K
T/K	Mole Fraction x₁	Mole Fraction x₂
298.2	0.0000	0.000 0104 Ref. 14
298.2	0.0773	0.0010
298.2	0.2865	0.0100
298.2	0.3459	0.0200
298.2	0.4002	0.0400
298.2	0.4276	0.0600
298.2	0.4438	0.0800
298.2	0.4540	0.1000
298.2	0.4601	0.1200
298.2	0.4634	0.1400
298.2	0.4647	0.1600
298.2	0.4642	0.1800
298.2	0.4625	0.2000
298.2	0.4596	0.2200
298.2	0.4558	0.2400
298.2	0.4512	0.2600
298.2	0.4458	0.2800
298.2	0.4397	0.3000
298.2	0.4331	0.3200
298.2	0.4259	0.3400
298.2	0.4182	0.3600
298.2	0.4100	0.3800
298.2	0.4014	0.4000
298.2	0.3924	0.4200
298.2	0.3830	0.4400
298.2	0.3732	0.4600
298.2	0.3630	0.4800
298.2	0.3525	0.5000
298.2	0.3417	0.5200
298.2	0.3305	0.5400
298.2	0.3191	0.5600
298.2	0.3073	0.5800
298.2	0.2952	0.6000
298.2	0.2829	0.6200
298.2	0.2702	0.6400
298.2	0.2573	0.6600
298.2	0.2441	0.6800
298.2	0.2307	0.7000
298.2	0.2170	0.7200
298.2	0.2030	0.7400
298.2	0.1888	0.7600
298.2	0.1743	0.7800
298.2	0.1596	0.8000
298.2	0.1447	0.8200
298.2	0.1295	0.8400
298.2	0.1141	0.8600
298.2	0.0984	0.8800
298.2	0.0825	0.9000
298.2	0.0664	0.9200
298.2	0.0501	0.9400
298.2	0.0335	0.9600
298.2	0.0167	0.9800
298.2	0.0082	0.9900
298.2	0.0000	0.9972 Ref. 14

View Figure 1 for this Evaluation

Notes:
Table 25  Number of experimental points in parentheses.

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

   1  Curtis, C.B., J. Phys. Chem. 2, 371 (1897-1898).
   2  Bonner, W.D., J. Phys. Chem. 14, 738 (1909-1910).
   3  Ormandy, W.R.; Craven, E.C., J. Inst. Petrol. Technol. 7, 325, 422 (1921).
   4  Tarasenkov, D.N.; Polozhentseva, E.N., Zh. Obshch. Khim. 2, 84 (1932).
   5  Washburn, R.E.; Beguin, A.E.; Beckord, O.C., J. Am. Chem. Soc. 61, 1694 (1939).
   6  Leikola, E., Suomen Kemistil B. 13, 13 (1940).
   7  Mondain-Monval, P.I.; Quiquerez, J., Bull. Soc. Chim. Fr. Mem. 7, 240 (1940).
   8  Arzhanov, P.G.; Komarova, L.F.; Garber, Yu.N., Zh. Prikl. Khim. (Leningrad) 48, 2089 (1975).
   9  Borisova, I.A.; Vatskova, V.G.; Gorbunov, A.I.; Sokolov, N.M., Khim. Prom-st (Moscow) 347 (1978).
   10  Bevia, F.R.; Rico, D.P.; Yagues, V.G., Fluid Phase Equilibra 23, 269 (1985).
   11  Ricna, K.; Matous, J.; Novak, J.P.; Kubicek, V., Collect. Czech. Chem. Commun. 54, 581 (1989).
   12  Letcher, T.M.; Siswana, P.M., Fluid Phase Equilib. 74, 203 (1992).
   13  Kafarov, V.V., ed., Spravochnik po Rastvorimosti Vol. 2, Troinye, Mnogokomponentnye Sistemy, Kniga II (Izd. Akademii Nauk SSSR, Moskva, 1963).
   14  Shaw, D.G., ed., Solubility Data Series, Vol. 37, Hydrocarbons with Water and Seawater, Part I: Hydrocarbons C5 to C7 (Pergamon, New York, 1989).