SDS Volume (2732)
Volume 62. Carbon Dioxide in Water and Aqueous Electrolyte Solutions, p None
Original Measurements
He, S.; Morse, J. W.; Geochim. Cosmochim. Acta 1993, 57, 3533-54.
Variables:
Room Temp:
273.15 - 363.15
$\pu{K}$
Pressure:
0.1032
$\pu{MPa}$
Molality (2):
m2/mol kg-1 = 0.01 - 0.9
mol/kg
Prepared by:
Method/Apparatus/Procedure:
Either pure $\ce{CO2}$ gas or $\ce{CO2}-\ce{N2}$ mixtures were used in the experiments to maintain a constant P($\ce{CO2}$). The $\ce{CO2}-\ce{N2}$ mixtures were made by pumping predetermined amounts of $\ce{CO2}$ and $\ce{N2}$ into a gas tank and their composition was verified by gas chromatography.
$\ce{CO2}$ or $\ce{CO2}-\ce{N2}$ gas mixtures were equilibrated with the aqueous solutions in a series of stirred water-jacketed reaction vessels with condensers. The gas was pre-moistured by first passing it through distilled water at the temperature of experiment. Fine bubbles were obtained by using gas-dispersion tubes. The bubbling rate was 90-95 mL/min.
The mole fraction of $\ce{CO2}$ in the $\ce{CO2}-\ce{N2}$ mixture was determined using a Hewlett Packard (5790A) gas chromatograph.
Source and Purity of Materials:
- Commercial; purity 99.9%
- Source not mentioned. Analytical reagent-grade which met ACS specifications.
Vacuum-dried before use. - 18 MΩ water obtained from a Milli-Q Super-Q water system.
Estimated Errors:
Ambient temperature: δT/K = ±0.1
Mass concentration (m/v) (1): δm1/m1 = ±0.012
δγ1/γ1 = ±0.04
Components:
- Carbon dioxide, $\ce{ CO2 }$; [124-38-9] NIST WebBook
- Potassium sulfate, $\ce{ K2SO4 }$; [7778-80-5] NIST WebBook
- Water, $\ce{ H2O }$; [7732-18-5] NIST WebBook
Experimental Data
| $T$ ($\pu{K}$) | m1 (mol/kg) | m2 (mol/kg) | ρ (g/cm3) | γ |
|---|---|---|---|---|
| 273.15 | 0.0741 | 0.01 | 1.0017 | 1.02 |
| 273.15 | 0.0693 | 0.1 | 1.0152 | 1.09 |
| 273.15 | 0.0671 | 0.2 | 1.0291 | 1.14 |
| 273.15 | 0.0647 | 0.3 | 1.0425 | 1.16 |
| 273.15 | 0.0598 | 0.4 | 1.0553 | 1.26 |
| 298.15 | 0.0299 | 0.1 | 1.0109 | 1.07 |
| 298.15 | 0.0281 | 0.2 | 1.0246 | 1.10 |
| 298.15 | 0.0279 | 0.3 | 1.0372 | 1.15 |
| 298.15 | 0.0264 | 0.4 | 1.0505 | 1.22 |
| 298.15 | 0.0244 | 0.6 | 1.0747 | 1.31 |
| 323.15 | 0.0179 | 0.02 | 0.9917 | 1.02 |
| 323.15 | 0.0173 | 0.1 | 1.0017 | 1.06 |
| 323.15 | 0.0155 | 0.5 | 1.0525 | 1.18 |
| 323.15 | 0.0146 | 0.81 | 1.0893 | 1.25 |
| 348.15 | 7.8 x 10-3 | 0.1 | 0.9884 | 1.04 |
| 348.15 | 7.5 x 10-3 | 0.3 | 1.0140 | 1.08 |
| 348.15 | 7.4 x 10-3 | 0.5 | 1.0388 | 1.09 |
| 348.15 | 7.1 x 10-3 | 0.7 | 1.0629 | 1.15 |
| 348.15 | 6.7 x 10-3 | 0.9 | 1.0862 | 1.20 |
| 363.15 | 3.4 x 10-3 | 0.1 | 0.9788 | 1.02 |
| 363.15 | 3.3 x 10-3 | 0.3 | 1.0046 | 1.05 |
| 363.15 | 3.2 x 10-3 | 0.5 | 1.0292 | 1.08 |
| 363.15 | 3.1 x 10-3 | 0.7 | 1.0523 | 1.11 |
| 363.15 | 3.0 x 10-3 | 0.9 | 1.0762 | 1.14 |
(a) Calculated by the compiler.
(b) m2 = molality of K2SO4
(c) p = density of solvent
(d) p1 = partial pressure of CO2
(e) m1 = molality of CO2
(f) γ1 = activity coefficient of CO2
