IUPAC-NIST Solubilities Database

IUPAC-NIST Solubility Database
NIST Standard Reference Database 106

Solubility System: Carbon dioxide with Ammonium chloride and Water

Components:
   (1) Ammonium chloride; NH4Cl; [12125-02-9]  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:
   Rumpf, B.; Nicolaisen, H.; Maurer, G., Ber. Bunsenges. Phys. Chem. 1994, 98, 1077-81.

Variables:
   Temperature = 313.14 K to 433.10 K
   Pressure = 313.14 K to 433.10 K
   Concentration = m₂/mol kg^-1 = near 4.00 and 6.00

Prepared By:
   Pirketta Scharlin

Experimental Remarks:

   The authors used Pitzer's semiempirical model to correlate the data. The model has been described in detail in Ref. 1. The dissociation of CO₂ can be neglected at the concentrations here. The system was treated as containing a non-dissociating gas, G and a completely dissociating electrolyte, MX. A temperature dependent interaction parameter, B°_{CO₂, NH₄Cl}, and a temperature independent interaction parameter, Γ_{CO₂, NH₄Cl, NH₄Cl}, were derived from the experimental data.

For the CO₂ + NH₄Cl + H₂O system the values are:
B°_{CO₂, NH₄Cl} = 0.2834 - 123.27(T/K)^-1 + 1551.29(T/K)^-2 + 3543·10³(T/K)^-3
and Γ_{CO₂, NH₄Cl, NH₄Cl} = - 0.0010.

The interaction parameters were also predicted from earlier measurements on the solubility of CO₂ in aqueous solutions of Na₂SO₄, (NH₄)₂SO₄ (Ref 1.) and NaCl (Ref. 2). The predicted values are:

B°_{CO₂, NH₄Cl} = 0.4206 - 187.48(T/K)^-1 + 691.287(T/K)^-2 + 6312 · 10³(T/K)^-3
and Γ_{CO₂, NH₄Cl, NH₄Cl} = - 0.0035.

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

Solubility of carbon dioxide in aqueous ammonium chloride. (m₂ = 3.994 mol/kg)
T/K	Pressure [MPa]	Molality m₁ [mol/kg]	m₁ Note
313.33	0.482	0.0980	b
313.22	1.157	0.2358	b
313.21	2.648	0.5086	b
313.21	4.320	0.7600	b
313.22	5.523	0.9050	b
313.21	7.354	1.0744	b
313.33	8.823	1.1519	b
333.12	0.689	0.0973	b
333.10	2.173	0.2918	b
333.11	3.897	0.4878	b
333.11	3.920	0.4906	b
333.11	5.997	0.6879	b
333.08	8.803	0.8856	b
353.13	0.0426	0.0	b
353.08	1.018	0.0995	b
353.10	2.504	0.2502	b
353.11	5.547	0.5034	b
353.13	9.692	0.7583	b
393.00	0.173	0.0	b
393.09	1.970	0.1273	b
393.07	3.433	0.2275	b
393.13	6.487	0.4064	b
393.12	8.458	0.5112	b
413.05	0.314	0.0	b
413.09	1.921	0.1005	b
413.06	4.413	0.2525	b
413.05	7.276	0.4036	b
413.08	9.276	0.5046	b
433.08	0.537	0.0	b
433.07	2.137	0.0998	b
433.07	2.212	0.0999	b
433.04	4.937	0.2510	b
433.10	6.676	0.3498	b
433.08	8.792	0.4516	b

Solubility of carbon dioxide in aqueous ammonium chloride. (m₂ = 5.992 mol/kg)
T/K	Pressure [MPa]	Molality m₁ [mol/kg]	m₁ Note
313.15	0.606	0.1263	b
313.14	1.231	0.2553	b
313.14	2.847	0.5461	b
313.14	4.674	0.8162	b
313.16	4.666	0.8171	b
313.16	6.521	1.0255	b
333.14	0.756	0.1043	b
333.15	2.305	0.3151	b
333.16	4.145	0.5265	b
333.12	6.507	0.7406	b
333.13	8.949	0.9010	b
353.11	0.0398	0.0	b
353.10	1.078	0.1070	b
353.11	2.688	0.2684	b
353.12	6.121	0.5404	b
353.11	9.139	0.7232	b
393.05	0.1606	0.0	b
393.04	1.543	0.0977	b
393.06	3.817	0.2450	b
393.06	6.355	0.3932	b
393.07	9.346	0.5398	b
413.05	0.294	0.0	b
413.07	1.901	0.0979	b
413.05	3.947	0.2170	b
413.06	7.401	0.3936	b
413.05	9.468	0.4909	b
433.09	0.5039	0.0	b
433.06	2.266	0.0990	b
433.04	4.153	0.2000	b
433.07	4.148	0.1991	b
433.09	6.051	0.2955	b
433.06	8.205	0.3937	b
433.08	9.245	0.4421	b

Notes:
   ^a  m₂ = molality of NH₄Cl
   ^b  m₁ = solubility of CO₂

Method/Apparatus/Procedure:
   The experimental equipment has been described in Ref. 1. It consists of a high pressure optical cell, thermostat, magnetic stirrer, thermocouples, and Pt resistance thermometer, pressure transducers and tanks for aqueous solutions, rinse water and solute gas.
The thermostated about 30 mL high pressure optical cell is filled with carbon dioxide. Pressure and temperature of the gas are measured after equilibration. A known amount of aqueous solvent is added which is slightly greater than that needed to completely dissolve the gas. The pressure in the cell is reduced stepwise by removing very small amounts of the liquid until the first stable bubble appears.
The mass of carbon dioxide is calculated from the Bender equation (3). The volume of the cell is known within 0.06 mL. The solvent density is from the literature.

Source and Purity of Materials:
   (1) Carbon dioxide. Messer Griesheim, Ludwigshafen, > 99.995 mol %, used as received.
   (2) Ammonium chloride. Riedel de Haen AG, Seelze, > 99.5 mass %. Degassed and dried under vacuum.
   (3) Water. Deionized and degassed by vacuum distillation.

Estimated Errors:

   Temperature: δT/K = ± 0.1
   Pressure: δp/p < ± 0.04 (at p up to 6 Mpa)
δp/p < ± 0.05 (at higher pressure)

References:
   1. Rumpf, B.; Maurer, G., Ber. Bunsenges. Phy. Chem. 1993, 97, 85-97.
   2. Rumpf, B.; Nicolaisen, H.; öcal, C. Maurer, G., J. Solution Chem. 1994, 23, 431-48.
   3. Bender, E., 5th Proc. Symp. Thermophys. Prop., ASME, NY, 1970, 227-35.