Components:
(1) Octane,
C8H18; [111-65-9]
NIST WebBook
(2) Water,
H2O; [7732-18-5]
NIST WebBook
Original Measurements
Heidman, J. L.; Tsonopoulos, C.; Brady, C. J.; Wilson, G. M.; A. I. Ch. E. J. 1985, 31, 376-84.
Variables:
Ambient temperature: 311 - 553 K
Pressure: 0.01 - 7.4 MPa
Prepared by:
Method/Apparatus/Procedure:
Experimental procedure was similar to that used in ref. 1. Hydrocarbons were determined by gas chromatography and water by Karl Fischer titration. Critical points were determined by the synthetic method using visual observation. This aspect of the procedure is discussed in detail in the paper.
Source and Purity of Materials:
- Aldrich 99+ mol%; water free purity greater than or equal to 99.9 mol%, checked by gas chromatography.
- Distilled; no details given.
Estimated Errors:
Ambient temperature: not stated.
Mass concentration (m/v) (1): ±5%, relative precision of replicate analyses.
Pressure: ±1%; type of error not stated.
References
Experimental Values:
Note: The three phase critical point was reported to be 539.1 ± 0.6 K, 7.37 ± 0.04 MPa and x1 = 4.61 × 10-4 (0.292 g(1)/100 g sln, compiler).The authors also report an equation which fit their own and literature data over the range 273-539 K, viz.
ln x1 = -343.1497 + 13862.49/T + 49.24609 ln T
ln x2 = -0.66037 - 7.1130 (Tr-1 - 1) - 0.67885 (1 - Tr)1/3 - 1.43381 (1 - Tr)
where Tr = T/539.1
Solubility of octane in water
| T (K) | P (MPa) | x1 | MR1 (g1/100 g sln)c |
|---|---|---|---|
| 310.9 | 1.03 x 10-2 | 1.2 x 10-7 | 7.6 x 10-5 |
| 366.5 | 1.17 x 10-1 | 4.8 x 10-7 | 3.0 x 10-4 |
| 422.0 | 6.55 x 10-1 | 3.8 x 10-6 | 2.4 x 10-3 |
| 479.5 | 2.51 | 4.0 x 10-5 | 2.5 x 10-2 |
| 536.1 | 7.03 | 3.5 x 10-4 | 2.2 x 10-1 |
| 552.8 | 8.86 | 6 x 10-4 | 3.8 x 10-1 |
(a) Estimated by the authors from pure component data. (b) Above three-phase equilibrium point.
Solubility of water in octane
| T (K) | P (MPa) | x2 | MR2 (g2/100 g sln)e |
|---|---|---|---|
| 310.9 | 1.03 x 10-2 | 1.00 x 10-3 | 1.58 x 10-2 |
| 366.5 | 1.17 x 10-1 | 6.2 x 10-3 | 9.8 x 10-2 |
| 422.0 | 6.55 x 10-1 | 3.94 x 10-2 | 6.22 x 10-1 |
| 477.6 | - | 1.26 x 10-1 | 2.22 |
| 533.1 | - | 3.87 x 10-1 | 9.05 |
| 539.1 | 7.41 | 5.27 x 10-1 | 14.9 |
| 550.4 | - | 5.49 x 10-1 | 16.1 |
(a) Estimated by the authors from pure component data. (b) Not specified. (c) Three phase critical point. (d) Above three phase critical point.
