IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: 2,2,4-Trimethylpentane with Water

Components:
   (1) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail
   (2) 2,2,4-Trimethylpentane; C8H18; [540-84-1]  NIST Chemistry WebBook for detail

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

Critical Evaluation:

   Quantitative solubility data for the 2,2,4-trimethylpentane (1) – water (2) system have been reported in the publications listed in Table 1.

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

1. THE SOLUBILITY OF 2,2,4-TRIMETHYLPENTANE (1) IN WATER (2)

Very few data are available for the solubility of 2,2,4-trimethylpentane in water making critical evaluation difficult. The datum of Baker (ref 2) is rejected as the temperature was not specified. All other reported values are collected in Table 2 with the exception of the datum of Krzyzanowska and Szeliga (ref 8) which does not appear to be independent of that of Price (ref 7) and has therefore been excluded from consideration.

At 298K where comparisons are possible, the values of McAuliffe (ref 4) and Polak and Lu (ref 5) are in reasonable agreement. The value reported by Price (ref 7) is much lower. Although Price’s data for many hydrocarbons in water are normally reliable, many of his values for the higher hydrocarbons are lower than other studies. However, in the absence of confirmatory studies it is not reasonable to reject Price’s value at this stage. However, it has not been included in the calculation of the “Best” values at 298K..

At other temperatures the “Best” values should be regarded with the caution in the absence of confirmatory studies.

2. SOLUBILITY OF WATER (2) IN 2,2,4-TRIMETHYLPENTANE (1)

The various reported values of the solubility of water in 2,2,4-trimethylpentane are collected in Table 3 and plotted in Figure 1.

The data are generally in poor agreement and the averaged “Best” values must be regarded with caution pending further studies. Generally, for many other systems investigated by these authors, the data of Englin et al. (ref 3) are reliable at T < 300K but are too high at higher temperatures. Application of the van’t Hoff equation to the data of Englin et al. and Bergengeim (ref 1) gives values of ΔH_s1n = 41.9 and 20.1 kJ mo1^-1 and ΔC_p,s1n =–100 and –1950 J K^-1 mo1^-1 respectively. Comparison of these data with other systems suggests that the values of Englin et al. are more realistic (although probably high at T > 300K). This system clearly warrants further investigation.

Experimental Data:   (Notes on the Nomenclature)

Table 1. Quantitative Solubility Studies of the 2, 2, 4-Trimethylpentane (1) - Water (2) System
Author	T/K	Reference	Solubility	Method
Berkengeim	273-313	1	(2) in (1)	Karl Fischer
Baker	unspecified	2	(1) in (2)	radiotracer
Englin et al.	273-323	3	(2) in (1)	analytical
McAuliffe	298	4	(1) in (2)	GLC
Polak and Lu	273, 298	5	mutual	GLC, Karl Fischer
Budantseva et al.	293	6	mutual	unspecified
Price	298	7	(1) in (2)	GLC
Krzyzanowska and Szeliga	298	8	(1) in (2)	GLC

Table 2. Tentative Values of the SOlubility of 2, 2, 4-Trimethylpentane (1) in Water (2)
T/K	Reference	Sol. Power	Solubility	Best Sol. Power	Best Solubility	Best Sol. Note	x₁ Power	x₁	x₁ Note
273	5	4	2.46 g(1)/100g sln	4	2.5 g(1)/100g sln	a	7	3.9	a
293	6	4	2 g(1)/100g sln	4	2 g(1)/100g sln	a	7	3	a
298	4, 5, 7	4	2.44, 2.05, 1.14 g(1)/100g sln	4	2.2 ± 0.2 g(1)/100g sln	a,b	7	3.5	a,b

Table 3. Tentative Values of the Solubility of Water (2) in 2, 2, 4 - Trimethylpentane
T/K	Reference	Sol. Power	Solubility	Sol. Note	Best Sol. Power	Best Solubility	Best Sol. Note	x₂ Power	x₂	x₂ Note
273	1, 3, 5	3	1.7*, 3.1, 2.3 g(2)/100g sln	c	3	2.4 ± 0.6 g(2)/100g sln	a	4	1.5	a
283	1, 3, 5	3	3.7, 5.9, 4.5* g(2)/100g sln	c	3	4.7 ± 0.9 g(2)/100g sln	a	4	2.9	a
293	1, 3, 5, 6	3	5.5, 11.5, 6.5*, 7.9 g(2)/100g sln	c	3	8 ± 2 g(2)/100g sln	a	4	5	a
298	1, 3, 5	3	6.2, 15.3, 8.0 g(2)/100g sln	c	3	10 ± 4 g(2)/100g sln	a	4	6	a
303	1, 3	3	7.0*, 20.1 g(2)/100g sln	c	3	20 g(2)/100g sln	a,b	4	10	a
313	1	3	8.0 g(2)/100g sln	c	-	-	-	-	-	-
323	3	3	53.8 g(2)/100g sln	c	3	50 g(2)/100g sln	a,b	4	30	a

View Figure 1 for this Evaluation

Notes:
Table 2^a  Obtained by averaging where appropriate; σ_n has no statistical significance.
Table 2^b  Average of data from ref 4 and 5 only, see text.
Table 3^a  Best values obtained by averaging where appropriate; σ_n has no statistical significance.
Table 3^b  Order of magnitude values only, see text.
Table 3^c  Values marked with an asterisk (*) have been obtained by the Evaluator by graphical interpolation of the authors' original data.

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

   1  Berkengeim, T.I., Zavod. Lab. 1941, 10, 592-4.
   2  Baker, E.G., Geochim. Cosmochim. Acta 1960, 19, 309-17.
   3  Englin, B.A.; Plate, A.F.; Tugolukov, V.M. Pryanishnikova, M.A., Khim. Tekhnol. Topl. Masel 1965, 10, 42-6.
   4  McAuliffe, C., J. Phys. Chem. 1966, 70, 1267-75.
   5  Polak, J.; Lu, B.C.Y., Can. J. Chem. 1973, 51, 4018-23.
   6  Budantseva, L.S.; Lesteva, T.M.; Nemstov, M.S., Zh. Fiz. Khim. 1976, 50, 1344. Deposited doc. 1976, VINITI 437-76.
   7  Price, L.C., Am. Assoc. Petrol. Geol. Bull. 1976, 60, 213-44.
   8  Krzyzanowska, T.; Szeliga, J., Nafta (Katowice) 1978, 12, 413-7.