SDS Volume (2615)
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 - 5.004
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. $\ce{CaCl2.2H2O}$ 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.
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
- 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) | ρ (g/cm3) | γ |
|---|---|---|---|---|
| 273.15 | 0.0697 | 0.104 | 1.0214 | 1.08 |
| 273.15 | 0.0537 | 1.021 | 1.0908 | 1.40 |
| 273.15 | 0.0346 | 2.036 | 1.1696 | 2.18 |
| 273.15 | 0.0257 | 2.998 | 1.2263 | 2.93 |
| 273.15 | 0.0169 | 4.027 | 1.2991 | 4.45 |
| 273.15 | 0.0104 | 5.001 | 1.3505 | 7.25 |
| 298.15 | 0.0301 | 0.102 | 1.0118 | 1.07 |
| 298.15 | 0.0214 | 1.001 | 1.1603 | 1.50 |
| 298.15 | 0.0142 | 2.002 | 1.1607 | 2.25 |
| 298.15 | 9.9 x 10-3 | 3.001 | 1.2290 | 3.25 |
| 298.15 | 6.7 x 10-3 | 5.004 | 1.3449 | 4.80 |
| 323.15 | 0.0141 | 0.105 | 1.0143 | 1.05 |
| 323.15 | 0.0102 | 0.976 | 1.0809 | 1.25 |
| 323.15 | 7.9 x 10-3 | 1.849 | 1.1435 | 1.69 |
| 323.15 | 6.3 x 10-3 | 2.706 | 1.2008 | 1.85 |
| 323.15 | 4.2 x 10-3 | 4.958 | 1.3321 | 2.56 |
| 348.15 | 7.7 x 10-3 | 0.101 | 0.9957 | 1.04 |
| 348.15 | 7.5 x 10-3 | 0.999 | 1.0639 | 1.08 |
| 348.15 | 6.9 x 10-3 | 2.001 | 1.1345 | 1.17 |
| 348.15 | 6.7 x 10-3 | 3.001 | 1.2000 | 1.20 |
| 348.15 | 5.8 x 10-3 | 5.001 | 1.3127 | 1.38 |
| 363.15 | 6.6 x 10-3 | 0.1 | 0.9915 | 1.05 |
| 363.15 | 6.4 x 10-3 | 1.0 | 1.0567 | 1.07 |
| 363.15 | 6.1 x 10-3 | 2.0 | 1.1245 | 1.14 |
| 363.15 | 5.9 x 10-3 | 3.0 | 1.1874 | 1.17 |
| 363.15 | 5.6 x 10-3 | 5.0 | 1.2987 | 1.22 |
(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 CaCl2
(a) Calculated by the compiler.
