IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Carbon dioxide with Sodium sulfate and Water

Components:
   (1) Sodium sulfate; Na2SO4; [7757-82-6]  NIST Chemistry WebBook for detail
   (2) Carbon dioxide; CO2; [124-38-9]  NIST Chemistry WebBook for detail
   (3) Water; H2O; [7732-18-5]  NIST Chemistry WebBook for detail

Original Measurements:
   Markham, A.A.; Kobe, K.A., J. Am. Chem. Soc. 1941, 63, 449-54.

Variables:
   Temperature = 298.15 K and 313.15 K
   Pressure = 101.325 kPa
   Concentration = m₂/mol kg^-1 = 0 - 1.5

Prepared By:
   D.M. Mason

Experimental Remarks:

   The authors fitted their data to equations:

S_m/S_o = am₂ + 1/(1 + bm₂), as follows:

t/°C                     a                 b
25               -0.0760               0.666
40               -0.0838               0.560

Experimental Data:   (Subscripts 1,2,3, ..., in column headings refer to components 1,2,3, ...)


t/°C	T/K	Keunen coefficient, S	S Note	α	α Note	Molality m₂ [mol/kg]
25	298.15	0.7587	b	0.7565	a	0.0
25	298.15	0.6381	b	0.6335	a	0.25
25	298.15	0.5399	b	0.5330	a	0.5
25	298.15	0.3957	b	0.3855	a	1
25	298.15	0.2943	b	0.2824	a	1.5
40	313.15	0.5173	b	0.5133	a	0.0
40	313.15	0.4450	b	0.4394	a	0.25
40	313.15	0.3804	b	0.3735	a	0.5
40	313.15	0.2872	b	0.2781	a	1
40	313.15	0.2175	b	0.2073	a	1.5

Notes:
   ^a  α = Bunsen coefficient [cm³ (STP) cm^-3 atm^-1].
   ^b  S = Kuenen coefficient [cm³ (STP) g^-1 (H₂O) atm^-1].

Method/Apparatus/Procedure:
   The principle of the Ostwald method was used in which the gas is agitated with a measured quantity of gas-free liquid and the decrease in volume of solution-saturated gas is measured in a burette over mercury. The pressure was adjusted to yield one atmosphere partial pressure of carbon dioxide. The volume of gas was reduced to 0 °C by the ideal gas law. Experiments were conducted to show that the agitation did not cause super-saturation.

Source and Purity of Materials:
   (1) Commercial cylinder, 99.8% pure.
   (2) Analytical grade.
   (3) Distilled and degassed.

Estimated Errors:
   Solubility: δα/α, δS/S = ± 0.002 (authors)
   Temperature: δT/K = ± 0.03 (authors)