IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: 1-Proponal with Benzene and Water

Components:
   (1) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail
   (2) 1-Proponal (n-propanol, propyl alcohol, n-propyl alcohol); C3H8O; [71-23-8]  NIST Chemistry WebBook for detail
   (3) Benzene; C6H6; [71-43-2]  NIST Chemistry WebBook for detail

Evaluator:
   A. Skrzecz, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland (1996.02)

Critical Evaluation:

      A survey of reported compositions along the saturation curve (sat), and compositions of coexisting phases in equilibrium (eq.) for the system 1-propanol-benzene-water is given in Table 41.

Saturation Curve The ternary system 1-propanol-benzene-water forms a miscibility gap of type 1. The miscibility gap observed to increase with decreasing temperature. Only one binary system, benzene-water, forms a miscibility gap. These binary data were compiled and critically evaluated in a previously published SDS volume.⁷ This critical evaluation is based on the original papers with the exception of data of Leikola,² which were taken from the handbook of Kafarov,⁸ this data set was also taken into account during evaluation but is not reported as a compilation sheet because it does not contribute further to knowledge of the system. Data of Letcher et al.⁶ were presented in the original paper only in graphical form and therefore are not reported as a compilation. Data of Udovenko and Mazanko⁵ were reported at saturation temperatures of mixtures containig a constant ratio of two components. A large number of experimental points (87) was reported over the temperature range 288-352 K, but were not used for constant temperature data comparisons. In Ref. 3 one point in the organic-rich phase at 293 K, x₁=0.4439, is rejected since it has an unrealistically high amount of 1-propanol. The comparison of recommended binary data (Ref. 7) was possible only with experimental data of McCants et al.⁴ at 310.9 K. The mutual solubility of the binary benzene-water system in Ref. 4 was reported to be x'₂=0.9871 and x"₂=0.0012, while the recommended values interpolated at the temperatures by the evaluator on the basis of Ref. 7 are x'₂=0.9954 and x"₂=0.000 44. Other references did not report information about the binary system. Equilibrium data, reported in Refs. 3, 4, and 5, were included in the evaluation of saturation the curve. All data are consistent with each data set as well as with one another. All are treated as tentative. Temperature of 293.2 K was selected and data of Leikola² and Denzler³ were fitted to the equation: x₁=a₁·z₁·ln(z₁)+a₂·z₂ ln(z₂)+a₃·z₁·z₂. where z₁=(x₂+0.5·x₁–x"₂₀)/(x'₂₀–x"₂₀), z₂=(x'₂₀–x₂–0.5·x₁)/(x'₂₀–x"₂₀), x₁, x₂-mole fraction of component (1) and (2) respectively, x'₂₀, x"₂₀-values of x₂ on the saturation curve which cuts the x₁=0 axis.
The equation was proposed by Hlavaty⁹ and also used with success by Letcher et al.¹⁰ for the description of saturation curves of the ternary alcohol-ether-water systems. This equation gives better results (smaller standard deviation) for the sytem than any other tested equations. The parameters obtained by the least-squares method for the whole range of saturation curve are: a₁=–0.018 96, a₂=0.462 78, a₃=2.394 28. The standard error of estimate was 0.0094. For selected concentrations of benzene in the mixture, the saturation curve was calculated and the results are presented in Table 42 and in Figure 21 as a solid line.

Phases in equilibrium    The phases in equilibrium were measured at constant temperatures: 293 K (Ref. 3), 298 K (Ref. 6), 303 K (Ref. 5), 311 K (Ref. 4), 318 K and 333 K (Ref. 5). The tie lines cover the whole area of miscibility gap, all together 61 tie lines were reported. They are consistent within each data set, within each region as well as between regions. Letcher and Siswana on the basis previous experiments, Ref. 6, calculated the plait point in Ref. 11. Characteristic points on binodal curve, plait point and maximum 1-propanol concentration, reported or estimated, are presented at selected temperatures in Table 43. At maximum 1-propanol concentration the errors estimated by the evaluator are 0.005 and 0.02 mole fraction of 1-propanol and benzene, respectively.
   The plait point changes very slightly with temperature. The concentration of 1-propanol at the plait point increases very slowly with decreasing temperature [from x₁=0.158 at 333 K (Ref. 5) to x₁=0.173 at 293 K (Ref. 3)]; while the concentration of benzene is nearly independent of temperature (it varied from 0.017 to 0.014). The experimental tie lines at 293.2 K, Ref. 3, are presented in Figure 21 together with the saturation curve as an example of the system property.

Experimental Data:   (Notes on the Nomenclature)

TABLE 41. Summary of experimental data for the system 1-propanol-benzene-water
Author	T/K	DataType	Reference
Holmes, 1918	288	sat. (1)	1
Leikola, 1940	293	sat. (8)	2
Denzler, 1945	293	sat. (17), eq. (12)	3
McCants et al., 1953	311	sat. (11), eq. (6)	4
Udovenko and Mazanko, 1963	288-352	sat. (87), eq. (38)	5
Letcher et al., 1990	298	sat. (14), eq. (5)	6

TABLE 42. Calculated compositions along the saturation curve at 293.2 K.
T/K	Mole Fraction x₁	Mole Fraction x₂
293.2	0.0000	0.000 406 Ref. 7
293.2	0.0490	0.0010
293.2	0.1612	0.0100
293.2	0.2190	0.0200
293.2	0.2898	0.0400
293.2	0.3353	0.0600
293.2	0.3676	0.0800
293.2	0.3916	0.1000
293.2	0.4096	0.1200
293.2	0.4231	0.1400
293.2	0.4329	0.1600
293.2	0.4399	0.1800
293.2	0.4444	0.2000
293.2	0.4469	0.2200
293.2	0.4475	0.2400
293.2	0.4466	0.2600
293.2	0.4443	0.2800
293.2	0.4407	0.3000
293.2	0.4360	0.3200
293.2	0.4303	0.3400
293.2	0.4237	0.3600
293.2	0.4162	0.3800
293.2	0.4080	0.4000
293.2	0.3990	0.4200
293.2	0.3894	0.4400
293.2	0.3792	0.4600
293.2	0.3684	0.4800
293.2	0.3571	0.5000
293.2	0.3453	0.5200
293.2	0.3331	0.5400
293.2	0.3204	0.5600
293.2	0.3074	0.5800
293.2	0.2939	0.6000
293.2	0.2802	0.6200
293.2	0.2661	0.6400
293.2	0.2517	0.6600
293.2	0.2370	0.6800
293.2	0.2221	0.7000
293.2	0.2070	0.7200
293.2	0.1916	0.7400
293.2	0.1761	0.7600
293.2	0.1604	0.7800
293.2	0.1446	0.8000
293.2	0.1286	0.8200
293.2	0.1127	0.8400
293.2	0.0967	0.8600
293.2	0.0807	0.8800
293.2	0.0648	0.9000
293.2	0.0492	0.9200
293.2	0.0339	0.9400
293.2	0.0193	0.9600
293.2	0.0061	0.9800
293.2	0.0000	0.9975 Ref. 7

TABLE 43. Charactistic points on the binodal curve of the system 1-propanol-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	0.173 Ref. 3	0.014 Ref. 3	Plait points
293.2	0.458 Ref. 3	0.220 Ref. 3	Max. C2H5OH concentration
293.2	-	-	Plait points
298.2	0.43 Ref. 6	0.20 Ref. 6	Max. C2H5OH concentration
298.2	0.18 Ref. 11	0.01 Ref. 11	Plait points
303.2	0.3917 Ref. 5	0.101 Ref. 5	Max. C2H5OH concentration
303.2	0.172 Ref. 5	0.014 Ref. 5	Plait points
310.9	0.396 Ref. 4	0.151 Ref. 4	Max. C2H5OH concentration
310.9	-	-	Plait points
318.2	0.412 Ref. 5	0.272 Ref. 5	Max. C2H5OH concentration
318.2	0.162 Ref. 5	0.015 Ref. 5	Plait points
333.2	0.390 Ref. 5	0.182 Ref. 5	Max. C2H5OH concentration
333.2	0.158 Ref. 5	0.017 Ref. 5	Plait points

View Figure 1 for this Evaluation

Notes:
Table 41  Number of experimental points in parentheses.

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

   1  Schweppe, J.L.; Lorah, J.R., Ind. Eng. Chem. 46, 2391 (1954).
   2  Leikola, E., Suomen Kemistil B. 13, 13 (1940).
   3  Denzler, C.G., J. Phys. Chem. 49, 358 (1945).
   4  Hartley, J., J. Soc. Chem. Ind. (London) 69, 60-1 (1950).
   5  Udovenko, V.V.; Mazanko, T.E., Zh. Fiz. Khim. 37, 1151 (1963).
   6  Letcher, T.M.; Sewry, J.; Radloff, S., S. Afr. J. Chem. 43, 56 (1990).
   7  Shaw, D.G., ed., Solubility Data Series, Vol. 37, Hydrocarbons with Water and Seawater, Part I: Hydrocarbons C5 to C7 (Pergamon, New York, 1989).
   8  Kafarov, V.V., ed., Spravochnik po Rastvorimosti Vol. 2, Troinye, Mnogokomponentnye Sistemy, Kniga II (Izd. Akademii Nauk SSSR, Moskva, 1963).
   9  Hlavaty, K., Collect. Czech. Chem. Commun. 37, 4005 (1972).
   10  Letcher, T.M.; Ravindran, S.; Radloff, S.E., Fluid Phase Equilib, 69, 251 (1991).
   11  Letcher, T.M.; Siswana, P.M., Fluid Phase Equilib. 74, 203 (1992).