SDS Volume
Volume 62. Carbon Dioxide in Water and Aqueous Electrolyte Solutions, p None
Source Publication
He, S.; Morse, J. W.; Geochim. Cosmochim. Acta 1993, 57, 3533-54.
Conditions:
Room Temp:
273.15 - 363.15
$\pu{K}$
Pressure:
0.1032
$\pu{MPa}$
Molality (2):
m2/mol kg-1 = 0.1 - 5.004
mol/kg
Compiler:
Methodology:
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.
Sample Information:
- Commercial; purity 99.9%
- Source not mentioned. Analytical reagent-grade which met ACS specifications. $\ce{CaCl2.2H2O}$ was weighed and dissolved in water. The concentration of $\ce{CaCl2}$ 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.
Measurement Errors:
Ambient temperature: δT/K = ±0.1
Mass concentration (m/v) (1): δm1/m1 = ±0.012
δγ1/γ1 = ±0.04
System Components:
- Carbon dioxide, $\ce{ CO2 }$; [124-38-9] NIST WebBook
- Calcium chloride, $\ce{ CaCl2 }$; [10043-52-4] NIST WebBook
- Water, $\ce{ H2O }$; [7732-18-5] NIST WebBook
Experimental Data
| $T$ ($\pu{K}$) | m1 (mol/kg) | m2 (mol/kg) | $\rho, (20^{\circ}C)$ (g/cm3) | γ |
|---|---|---|---|---|
| 273.15 | 0.0697e | 0.104b | 1.0214c | 1.08f |
| 273.15 | 0.0537e | 1.021b | 1.0908c | 1.40f |
| 273.15 | 0.0346e | 2.036b | 1.1696c | 2.18f |
| 273.15 | 0.0257e | 2.998b | 1.2263c | 2.93f |
| 273.15 | 0.0169e | 4.027b | 1.2991c | 4.45f |
| 273.15 | 0.0104e | 5.001b | 1.3505c | 7.25f |
| 298.15 | 0.0301e | 0.102b | 1.0118c | 1.07f |
| 298.15 | 0.0214e | 1.001b | 1.1603c | 1.50f |
| 298.15 | 0.0142e | 2.002b | 1.1607c | 2.25f |
| 298.15 | 9.9 x 10-3e | 3.001b | 1.2290c | 3.25f |
| 298.15 | 6.7 x 10-3e | 5.004b | 1.3449c | 4.80f |
| 323.15 | 0.0141e | 0.105b | 1.0143c | 1.05f |
| 323.15 | 0.0102e | 0.976b | 1.0809c | 1.25f |
| 323.15 | 7.9 x 10-3e | 1.849b | 1.1435c | 1.69f |
| 323.15 | 6.3 x 10-3e | 2.706b | 1.2008c | 1.85f |
| 323.15 | 4.2 x 10-3e | 4.958b | 1.3321c | 2.56f |
| 348.15 | 7.7 x 10-3e | 0.101b | 0.9957c | 1.04f |
| 348.15 | 7.5 x 10-3e | 0.999b | 1.0639c | 1.08f |
| 348.15 | 6.9 x 10-3e | 2.001b | 1.1345c | 1.17f |
| 348.15 | 6.7 x 10-3e | 3.001b | 1.2000c | 1.20f |
| 348.15 | 5.8 x 10-3e | 5.001b | 1.3127c | 1.38f |
| 363.15 | 6.6 x 10-3e | 0.1b | 0.9915c | 1.05f |
| 363.15 | 6.4 x 10-3e | 1.0b | 1.0567c | 1.07f |
| 363.15 | 6.1 x 10-3e | 2.0b | 1.1245c | 1.14f |
| 363.15 | 5.9 x 10-3e | 3.0b | 1.1874c | 1.17f |
| 363.15 | 5.6 x 10-3e | 5.0b | 1.2987c | 1.22f |
(a) Calculated by the compiler.
(b) m2 = molality of CaCl2
(c) p = density of solvent
(d) p1 = partial pressure of CO2
(e) m1 = molality of CO2
(f) γ1 = activity coefficient of CO2


