IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Ethylcyclohexane with Water

Components:
   (1) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail
   (2) Ethylcyclohexane; C8H16; [1678-91-7]  NIST Chemistry WebBook for detail

Evaluator:
   G.T. Hefter, School of Mathematical and Physical Sciences, Murdoch University, Perth, W.A., Australia. May 1986.

Critical Evaluation:

   Quantitative solubility data for the ethylcyclohexane (1) –water (2) system have been reported in the publications listed in Table 1.

The original data in both of these publications are compiled in the Data Sheets immediately following this Critical Evaluation. For convenience further discussion of this system is in two parts.

1. SOLUBILITY OF ETHYLCYCLOHEXANE (1) IN WATER (2)

This system almost certainly exhibits type III phase behavior (see introductory material at the beginning of this volume). The phase diagram is similar to that of ethylbenzene and water.

The solubility of ethylcyclohexane in water at elevated temperatures and system pressures along the three phase equilibrium line have been investigated by Guseva and Parnov (ref 1) and Heidman et al. (ref 2). Their results are summarized in Table 2 and plotted in Figure 1. The agreement is very poor. However, it may be noted (ref 1) that the values reported by Guseva and Parnov at higher temperatures approach those of cyclohexane, which is unreasonable. It may also be noted that the data of Guseva and Parnov often differ markedly from Recommended values in other systems. The data of Heidman et al. are thus considered Tentative.

Heidman et al. report a three phase critical end point at 561.4 ± 0.6 K, 9.93 ± 0.04 MPa and x₁ = 3.35 x 10^-3 (2.05 g(1)/100g s1n, Evaluator).

2. SOLUBILITY OF WATER (2) IN ETHYLCYCLOHEXANE (1)

As only the data of Heidman et al. (ref 2) are available on the solubility of water in ethylcyclohexane (Table 1) no Critical Evaluation of water is possible. The interested user is referred to the appropriate Data Sheet for the experimental values.

Experimental Data:   (Notes on the Nomenclature)

Table 1. Quantitative Solubility Studies of the Eythylcyclohexane (1) - Water (2) System
Author	T/K	Reference	Solubility	Method	Method Note
Guseva and Parnov	352-486	1	(1) in (2)	unspecified	a
Heidman et al.	311-561	2	mutual	GLC, Karl Fischer	-

Table 2. Tentative Solubility Values ofr Ethylcyclohexane (1) in Water (2) at the Three-Phase Equilibrium Pressure
T/K	Reference	Sol. Power	Solubility	Sol. Note	Best Sol. Power	Best Solubility	Best Sol. Note	x₁ Power	x₁	x₁ Note
313	2	2	0.066 g(1)/100g sln	a	2	0.07 g(1)/100g sln	b	4	0.01	b
323	2	2	0.074 g(1)/100g sln	a	2	0.07 g(1)/100g sln	b	4	0.011	b
333	2	2	0.086 g(1)/100g sln	a	2	0.07 g(1)/100g sln	b	4	0.014	b
343	2	2	0.10 g(1)/100g sln	a	2	0.10 g(1)/100g sln	b	4	0.016	b
353	1, 2	2	0.5, 0.13 g(1)/100g sln	a	2	0.13 g(1)/100g sln	b	4	0.020	b
363	1, 2	2	0.8, 0.16 g(1)/100g sln	a	2	0.16 g(1)/100g sln	b	4	0.026	b
373	1, 2	2	1.3, 0.21 g(1)/100g sln	a	2	0.21 g(1)/100g sln	b	4	0.034	b
393	1, 2	2	2.2, 0.55 g(1)/100g sln	a	2	0.55 g(1)/100g sln	b	4	0.088	b
413	1, 2	2	3.7, 0.95 g(1)/100g sln	a	2	0.95 g(1)/100g sln	b	4	0.15	b
433	1, 2	2	6.5, 1.6 g(1)/100g sln	a	2	1.6 g(1)/100g sln	b	4	0.26	b
453	1, 2	2	16.0, 2.8 g(1)/100g sln	a	2	2.8 g(1)/100g sln	b	4	0.45	b
473	1, 2	2	27.0, 5.5 g(1)/100g sln	a	2	5.5 g(1)/100g sln	b	4	0.9	b
493	2	2	16 g(1)/100g sln	a	2	16 g(1)/100g sln	b	4	2.2	b
513	2	2	34 g(1)/100g sln	a	2	34 g(1)/100g sln	b	4	5.2	b
533	2	2	65 g(1)/100g sln	a	2	65 g(1)/100g sln	b	4	10.4	b
553	2	2	150 g(1)/100g sln	a	2	150 g(1)/100g sln	b	4	24.0	b

View Figure 1 for this Evaluation

Notes:
Table 1^a  Probably using the synthetic method.
Table 2^a  All data obtained by graphical or algebraic interpolation by the Evaluator of the authors' original data.
Table 2^b  Rounded values from ref 2; data from ref 1 not included in "Best" values, see text.

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

   1  Guseva, A.N.; Parnov, E.I., Vestn. Mosk. Univ. Khim. 1964, 19, 77-8.
   2  Heidman, J.L.; Tsonopoulos, C.; Brady, C.J.; Wilson, G.M., A. I. Ch. E. J. 1985, 31, 376-84.