SDS Volume (2598)
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 = 0.1 - 5.021
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. $\ce{MgCl2.6H2O}$ was weighed and dissolved in water. The concentration of $\ce{MgCl2}$ in solutions was determined by analyzing $\ce{Cl-}$ concentration via $\ce{AgNO3}$ titration in stock solutions.
- 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
- Magnesium chloride, $\ce{ MgCl2 }$; [7786-30-3] 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 | 0.0703 | 0.1 | 1.0090 | 1.07 |
| 273.15 | 0.0492 | 1.0 | 0.0732 | 1.53 |
| 273.15 | 0.0357 | 2.0 | 0.1430 | 2.11 |
| 273.15 | 0.0249 | 3.0 | 0.1980 | 3.03 |
| 273.15 | 0.0156 | 4.0 | 0.2530 | 4.83 |
| 273.15 | 0.0102 | 5.0 | 0.3014 | 7.52 |
| 298.15 | 0.030 | 0.1 | 1.0056 | 1.07 |
| 298.15 | 0.0218 | 1.0 | 1.0680 | 1.47 |
| 298.15 | 0.0171 | 2.0 | 1.1342 | 2.25 |
| 298.15 | 9.9 x 10-3 | 3.0 | 1.1917 | 3.24 |
| 298.15 | 6.7 x 10-3 | 5.0 | 1.2948 | 4.83 |
| 323.15 | 0.0158 | 0.215 | 1.0049 | 1.06 |
| 323.15 | 0.0155 | 1.128 | 1.0669 | 1.23 |
| 323.15 | 0.0109 | 1.831 | 1.1119 | 1.52 |
| 323.15 | 9.6 x 10-3 | 3.024 | 1.1827 | 1.73 |
| 323.15 | 8.7 x 10-3 | 4.021 | 1.1368 | 1.91 |
| 323.15 | 7.5 x 10-3 | 5.021 | 1.2862 | 2.22 |
| 348.15 | 7.7 x 10-3 | 0.1 | 0.9842 | 1.05 |
| 348.15 | 7.3 x 10-3 | 1.0 | 1.0460 | 1.11 |
| 348.15 | 6.6 x 10-3 | 2.0 | 1.1109 | 1.23 |
| 348.15 | 6.3 x 10-3 | 3.0 | 1.1701 | 1.28 |
| 348.15 | 5.7 x 10-3 | 5.0 | 1.2742 | 1.42 |
| 363.15 | 3.3 x 10-3 | 0.1 | 0.9751 | 1.04 |
| 363.15 | 3.1 x 10-3 | 1.0 | 1.0376 | 1.10 |
| 363.15 | 2.9 x 10-3 | 2.0 | 1.1307 | 1.23 |
| 363.15 | 2.7 x 10-3 | 3.0 | 1.1629 | 1.27 |
| 363.15 | 2.4 x 10-3 | 5.0 | 1.2676 | 1.40 |
(f) γ1 = activity coefficient of CO2
(e) m1 = molality of CO2
(d) p1 = partial pressure of CO2
(c) p = density of solvent
(b) m2 = molality of MgCl2
(a) Calculated by compiler
