2-Methylbutane with Water (IUPAC SDS Volume 37)
Evaluator
Glenn T. Hefter School of Mathematical and Physical Sciences, Murdoch University
Evaluation
Quantitative solubility data for the 2-methylbutane (1) and 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.

In the Tables, which follow, solubility obtained by the Evaluator by graphical interpolation of original measurements in the Data Sheets are indicated by an asterisk (*). 'Best' values have been obtained, where appropriate, by simple averaging. Uncertainty limits (σn) attached to these values do not have statistical significance and should be regarded only as a convenient representation of the spread of values rather than error limits.

For convenience, further discussion of this system will be divided into two parts.


1. THE SOLUBILITY OF 2 METHYLBUTANE (1) IN WATER (2)
The solubility data for 2-methylbutane in water are listed in Table 2 and are also plotted in Figure 1 . The data of Krzyzanowska and Szeliga (ref 7) have been excluded from this Evaluation as they do not appear to be independent of those reported by Price (ref 6).

At 298K, where comparison amongst independent values is possible, agreement is excellent. This gives added confidence to the values at other temperatures. A possible exception may be the value of Polak and Lu (ref 5) at 273 K which appears a little high (even though some increase in solubility of hydrocarbons in water is usually observed as the temperature approaches 273 K, e.g. the benzene-water system).



2. THE SOLUBILITY OF WATER (2) IN 2-METHYLBUTANE (1)

The solubility data for water in 2-methylbutane are listed in Table 3 and plotted in Figure 2 . In general the reported values are in reasonable agreement. The only exception appears to be the data of Pavlova et al. (ref 4) which are higher than other values. Although there are insufficient independent data to justify outright rejection of the values of Pavlova et al. at this stage, nevertheless, their data have not been used in determining 'best' values (Table 3) and should be regarded with caution.

Figures
Solubility graph
Figure 1. Solubility of 2-methylbutane in water: ref 4 (x); average of ref 3-6 (o); ref 5 (●), but see text.
Solubility graph
Figure 2. Solubility of water in 2-methylbutane: ref 1 (x); ref 2 (△); ref 4 (O), ref 5 (●).
Sources:

7 Krzyzanowska, T.; Szeliga, J.; Nafta (Katowice) 1978, 12, 413-7.
5 Polak, J.; Lu, B. C. Y.; Can. J. Chem. 1973, 51, 4018-23.
1 Black, C.; Joris, G. G.; Taylor, H. S.; J. Chem. Phys. 1948, 16, 537-43.
6 Price, L. C.; Am. Assoc. Petrol. Geol. Bull. 1976, 60, 213-44.
4 Pavlova, S. P.; Pavlov, S. Yu.; Serafimov, L. A.; Kofman, L. S.; Promyshlennost. Sinteticheskogo Kauchuka 1966, 3, 18-20.
3 McAuliffe, C.; J. Phys. Chem. 1966, 70, 1267-1275.
2 Englin, B. A.; Plate, A. F.; Tugolukov, V. M. Pryanishnikova, M. A.; Chem. Technol. Fuels Oils, 1965, 1(9), 722-726.