IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: 1-Butanol with Benzene and Water

Components:
   (1) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail
   (2) 1-Butanol (n-butanol, butyl alcohol, n-butyl alcohol); C4H10O; [71-36-3]  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 (1997.03)

Critical Evaluation:

      A survey of reported compositions along the saturation curve (sat), and compositions of coexisting phases in equilibrium (eq.) for the system 1-butanol-benzene-water is given in Table 72.

Saturation curve The system 1-butanol-benzene-water forms a miscibility gap of type 2. Two binary systems, 1-butanol-water are partially miscible. The data of these systems were compiled and critically evaluated in previously published SDS volumes, Refs. 5 and 6, respectively. Data on the saturation curve of the organic-rich phase were presented in all four references, while data for the water-rich phase were presented only in Ref. 2 as saturation compositions and as a part of equilibrium data. Data of Letcher et al.⁴ were presented in graphical form only and therefore are not presented here as a commpilation sheet. The data of Staveley et al.³ show the relationship of saturation composition to temperature; the data describe the region of low 1-butanol concentrations (<0.1 mole fraction) and high benzene concentrations (>0.88 mole fraction). The paper of Peraksis¹ at 292 K reports a much smaller solubility gap than other data sets at slightly higher temperatures. This paper also reports outlying results for other alcohol-benzene-water systems and therefore these data are rejected and not compiled. The other data sets are treated as tentative. The temperature of 298.2 K as a standard temperature in which various alcohol-hydrocarbon-water systems are presented, was chosen to present the behavior of the system in Figure 38 . The recommended values of mutual solubility at 298.2 K are x'₂=0.9970 and x"₂=0.000 409 for benzene-water system⁵ and x'₁=0.488, x"₁=0.0191 for 1-butanol-water.⁶ The maximum 1-butanol concentration in organic-rich phase of this ternary system was observed to be x₁=0.532, Ref. 2; similar values were presented as a graph in Ref. 4. The water-rich phase composition are very close to the side of concentration triangle diagram and are consistent with recommended binary data.^5,6

Phases in equilibrium Compositions of coexisting phases in equilibrium of the ternary 1-butanol-benzene-water system were reported by Washburn and Strandskov² at 298.2 K and 308 K and cover the whole range of the miscibility gap. Graphical data of Letcher et al.⁴ at 298 K were not taken into account. The tie lines are consistent within each data set and are consistent with one another. Both equilibrium data sets are treated as tentative. The experimental tie lines at 298.2 K are presented in Figure 38 .

Experimental Data: (Notes on the Nomenclature)

TABLE 72. Summary of experimental data for the system 1-butanol-benzene-water
Author	T/K	DataType	Reference
Perrakis, 1925	292	sat. (10)	1
Washburn and Strandskov, 1944	298, 308	sat. (20), eq. (28)	2
Staveley et al., 1951	287-333	sat. (28)	3
Letcher et al., 1990	298	sat. (14), eq. (3)	4

View Figure 1 for this Evaluation

Notes:
Table 72  Number of experimental points in parentheses.

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

   1  Perrakis, N., J. Chim. Phys. Chim. Biol. 22, 280 (1925).
   2  Washburn, E.R.; Beguin, A.E., J. Am. Chem. Soc. 62, 579 (1940).
   3  Staveley, L.A.K.; Johns, R.G.S.; Moore, B.C., J. Chem. Soc. 1951, 2516-23.
   4  Letcher, T.M.; Sewry, J.; Radloff, S., S. Afr. J. Chem. 43, 56 (1990).
   5  Shaw, D.G., ed., Solubility Data Series, Vol. 37, Hydrocarbons with Water and Seawater, Part I: Hydrocarbons C5 to C7 (Pergamon, New York, 1989).
   6  Barton, A.F. M., ed., Solubility Data Series, Vol. 15, Alcohols with Water (Pergamon, New York 1984).