IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Carbon dioxide with Sodium nitrate and Water

Components:
   (1) Sodium nitrate; NaNO3; [7631-99-4]  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 = 273.35 K and 298.15 K
   Pressure = 273.35 K and 298.15 K
   Concentration = m₂/mol kg^-1 = 0 - 4

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
0.2                     -0.0054                     0.240
25                     -0.0050                      0.150

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]
0.2	273.35	1.7025	b	1.7023	a	0.0
0.2	273.35	1.6247	b	1.6167	a	0.2
0.2	273.35	1.5229	b	1.5040	a	0.5
0.2	273.35	0.9589	b	0.8840	a	3
0.2	273.35	0.5099	b	0.4055	a	4
25	298.15	0.7587	b	0.7565	a	0.0
25	298.15	0.7458	b	0.7415	a	0.1
25	298.15	0.7352	b	0.7289	a	0.2
25	298.15	0.7069	b	0.6946	a	0.5
25	298.15	0.6562	b	0.6352	a	1
25	298.15	0.5758	b	0.5406	a	2
25	298.15	0.5109	b	0.4659	a	3
25	298.15	0.3151	b	0.2474	a	4

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 = <± 0.1 at 0.2 °C, ± 0.03 at 25 °C (authors)