Model III Data

The System

The sources of data used to determine mixture parameters W, Q and U in the activity coefficient equations for this ternary (3 ion) system are listed in Table 14 of Clegg et al. (1998b). Fits of the model are described in section 3.16 of that paper. The following types of data were used:

Solubilities of the solids NH4Cl(s) and NaCl(s) in the ternary solutions.
Osmotic coefficients from isopiestic measurements.

References: S. L. Clegg, P. Brimblecombe and A. S. Wexler (1998b) J. Phys. Chem. A 102, 2155-2171.

Weights

The values listed in the tables below are based upon those used in the fits of the model. However, they have been normalised for each type of measurement so that the maximum weight for any data point in each table is always unity. Points given zero weight are those which either appear to be in error, or are used for comparison only (and were not fitted). Points with a weight of "-" are outside the temperature or concentration limits of the current model, and have not been assessed for accuracy.

The Data

The experimental data used to fit the activity coefficient model are listed in the tables below. Notes at the end of each one define the tabulated quantities, and identify the sources of the measurements.

(1) Solubilities of Solid Phases

    mNaCl    mNH4Cl     t     solid    ref.     weight                       
    4.089    4.278    18.70    99    a(2458)      -        
    4.515    4.130    17.00    99    a(2459)      -        
    4.890    2.734     0.00    99    a(2460)      -        
    0.000    5.591     0.00    99    a(2460)      -                                                     
    6.140    0.000    15.00    99    a(2460)      -        
    5.586    1.071    15.00    99    a(2460)      -        
    5.130    2.222    15.00    99    a(2460)      -        
    4.645    3.483    15.00    99    a(2460)      -        
    4.554    3.715    15.00    99    a(2460)      -        
    3.574    4.200    15.00    99    a(2460)      -        
    2.095    5.179    15.00    99    a(2460)      -        
    1.019    5.910    15.00    99    a(2460)      -        
    0.000    6.666    15.00    99    a(2460)      -                                                                 
    4.261    4.776    30.00    99    a(2460)      -                                      
    4.766    2.718     0.00     1    a(2461)      -                                      
    4.766    2.718     0.00     2    a(2461)      -       
    4.284    4.502    25.00     1    a(2461)     1.0      
    4.284    4.502    25.00     2    a(2461)     1.0      
    4.502    3.370    10.00     1    a(2461)      -       
    4.502    3.370    10.00     2    a(2461)      -       
    4.654    3.794    15.00    99    a(2461)      -       
    3.335   11.498   100.00    99    a(2461)      -       
    0.000    5.553     0.00     2    a(2462)      -       
    1.471    4.578     0.00     2    a(2462)      -       
    4.433    2.930     0.00     2    a(2462)      -       
    4.433    2.930     0.00     1    a(2462)      -       
    6.093    0.000     0.00     1    a(2462)      -       
    0.000    6.603    15.00     2    a(2462)      -       
    2.684    4.767    15.00     2    a(2462)      -       
    4.225    3.795    15.00     2    a(2462)      -       
    4.225    3.795    15.00     1    a(2462)      -       
    4.652    3.157    15.00     1    a(2462)      -       
    4.977    2.989    25.00     1    a(2462)     1.0      
    4.081    3.738    10.60     2    a(2462)      -       
    4.114    4.166    18.25     2    a(2462)      -                                      
    4.943    2.990    15.90     1    a(2462)      -                                      
    4.977    2.989    24.10     1    a(2462)      -                                      
    4.871    2.728     0.00     1    a(2463)      -                                      
    4.871    2.728     0.00     2    a(2463)      -                                      
    2.581    3.886     0.00     2    a(2463)      -                                      
    4.367    4.437    25.00     1    a(2463)     1.0
    4.367    4.437    25.00     2    a(2463)     1.0
    2.188    5.775    25.00     2    a(2463)     1.0
    4.074    5.571    40.00     1    a(2463)      -                                      
    4.074    5.571    40.00     2    a(2463)      -                                      
    4.485    7.615    60.00     1    a(2463)      -                                      
    4.485    7.615    60.00     2    a(2463)      -                                      
    1.997    8.610    60.00     2    a(2463)      -                                      
    3.510    9.427    80.00     1    a(2463)      -                                      
    3.510    9.427    80.00     2    a(2463)      -                                      
    4.838    2.742     0.00     1    a(2465)      -                                      
    4.838    2.742     0.00     2    a(2465)      -                                      
    4.428    4.081    20.00     1    a(2465)      -                                      
    4.428    4.081    20.00     2    a(2465)      -                                      
    3.858    6.651    50.00     1    a(2465)      -                                      
    3.858    6.651    50.00     2    a(2465)      -                                      
    4.001    9.144    75.00     1    a(2465)      -                                      
    4.001    9.144    75.00     2    a(2465)      -                                      
    0.264    1.321   -5.307     0    a(2466)      -                                       
    0.526    1.052   -5.304     0    a(2466)      -                                       
    0.785    0.785   -5.303     0    a(2466)      -                                       
    1.041    0.520   -5.291     0    a(2466)      -                                       
    1.295    0.259   -5.303     0    a(2466)      -                                       
    0.270    1.890   -7.248     0    a(2466)      -                                       
    0.536    1.609   -7.257     0    a(2466)      -                                       
    0.802    1.337   -7.295     0    a(2466)      -                                       
    1.061    1.061   -7.275     0    a(2466)      -                                       
    1.321    0.793   -7.295     0    a(2466)      -                                       
    1.579    0.526   -7.272     0    a(2466)      -                                       
    1.833    0.262   -7.302     0    a(2466)      -                                       
    6.024    0.000     0.00     1    a(2467)      -                                      
    4.765    2.676     0.00     1    a(2467)      -                                      
    4.765    2.676     0.00     2    a(2467)      -                                      
    3.044    3.603     0.00     2    a(2467)      -                                      
    0.000    5.590     0.00     2    a(2467)      -                                      
    6.040    0.000    10.00     1    a(2467)      -                                      
    4.892    2.579    10.00     1    a(2467)      -                                      
    4.603    3.429    10.00     1    a(2467)      -                                      
    4.603    3.429    10.00     2    a(2467)      -                                      
    2.856    4.430    10.00     2    a(2467)      -                                      
    0.000    6.205    10.00     2    a(2467)      -                                      
    6.090    0.000    20.00     1    a(2467)      -                                      
    5.885    0.513    20.00     1    a(2467)      -                                      
    4.910    2.898    20.00     1    a(2467)      -                                      
    4.416    4.021    20.00     1    a(2467)      -                                      
    4.416    4.021    20.00     2    a(2467)      -                                      
    4.090    4.152    20.00     2    a(2467)      -                                      
    1.949    5.663    20.00     2    a(2467)      -                                      
    0.000    7.010    20.00     2    a(2467)      -                                      
    5.658    0.000   -10.00     1    a(2467)      -                                      
    4.704    2.280   -10.00     1    a(2467)      -                                      
    4.704    2.280   -10.00     2    a(2467)      -                                      
    2.548    3.447   -10.00     2    a(2467)      -                                      
    0.000    4.916   -10.00     2    a(2467)      -                                      
    6.175    0.000    35.00     1    a(2467)      -                                      
    4.091    5.178    35.00     1    a(2467)      -                                      
    4.091    5.178    35.00     2    a(2467)      -                                      
    3.413    5.740    35.00     2    a(2467)      -                                      
    0.000    8.112    35.00     2    a(2467)      -                                      
    6.297    0.000    50.00     1    a(2467)      -                                      
    5.853    1.075    50.00     1    a(2467)      -                                      
    5.167    2.151    50.00     1    a(2467)      -                                      
    5.306    2.803    50.00     1    a(2467)      -                                      
    4.088    6.168    50.00     1    a(2467)      -                                      
    4.088    6.168    50.00     2    a(2467)      -                                      
    2.671    7.308    50.00     2    a(2467)      -                                      
    1.555    8.057    50.00     2    a(2467)      -                                      
    1.009    8.533    50.00     2    a(2467)      -                                      
    0.000    9.162    50.00     2    a(2467)      -                                      
    6.364    0.000    65.00     1    a(2467)      -                                      
    6.096    7.733    65.00     1    a(2467)      -                                      
    3.539    7.981    65.00     1    a(2467)      -                                      
    3.539    7.981    65.00     2    a(2467)      -                                      
    2.292    8.862    65.00     2    a(2467)      -                                      
    0.000   10.562    65.00     2    a(2467)      -                                      
    6.399    0.000    80.00     1    a(2467)      -                                      
    6.280    0.305    80.00     1    a(2467)      -                                      
    3.370    9.476    80.00     1    a(2467)      -                                      
    3.370    9.476    80.00     2    a(2467)      -                                      
    2.893    9.718    80.00     2    a(2467)      -                                      
    6.122    0.000    15.00     1    a(2468)      -                                      
    5.731    0.759    15.00     1    a(2468)      -                                      
    5.376    1.596    15.00     1    a(2468)      -                                      
    5.014    2.420    15.00     1    a(2468)      -                                      
    4.421    3.766    15.00     1    a(2468)      -                                      
    4.421    3.766    15.00     2    a(2468)      -                                      
    3.227    4.487    15.00     2    a(2468)      -                                      
    2.338    5.082    15.00     2    a(2468)      -                                      
    1.766    5.449    15.00     2    a(2469)      -                                      
    0.727    6.138    15.00     2    a(2469)      -                                      
    0.000    6.589    15.00     2    a(2469)      -                                      
    6.150    0.000    25.00     1    a(2470)     1.0                                     
    5.586    1.499    25.00     1    a(2470)     1.0                                     
    5.317    2.329    25.00     1    a(2470)      -                                      
    4.920    3.495    25.00     1    a(2470)      -                                      
    4.422    4.435    25.00     1    a(2470)     1.0                                     
    4.422    4.435    25.00     2    a(2470)     1.0                                     
    2.673    5.601    25.00     2    a(2470)     1.0                                     
    1.326    6.544    25.00     2    a(2470)     1.0                                     
    0.000    7.397    25.00     2    a(2470)     1.0                                     
    6.297    0.000    50.00     1    a(2470)      -                                      
    5.175    3.302    50.00     1    a(2470)      -                                      
    4.353    5.444    50.00     1    a(2470)      -                                      
    3.904    6.601    50.00     1    a(2470)      -                                      
    3.904    6.601    50.00     2    a(2470)      -                                      
    3.404    6.897    50.00     2    a(2470)      -                                      
    1.992    8.104    50.00     2    a(2470)      -                                      
    0.773    8.799    50.00     2    a(2470)      -                                      
    0.000    9.439    50.00     2    a(2470)      -                                      
    6.730    0.000   100.00     1    a(2470)      -                                      
    6.329    1.224   100.00     1    a(2470)      -                                      
    5.481    3.643   100.00     1    a(2470)      -                                      
    4.972    6.055   100.00     1    a(2470)      -                                      
    4.156    9.058   100.00     1    a(2470)      -                                      
    3.924    9.896   100.00     1    a(2470)      -                                      
    3.363   11.590   100.00     1    a(2470)      -                                      
    3.363   11.590   100.00     2    a(2470)      -                                      
    0.684   13.764   100.00     2    a(2470)      -                                      
    0.000   14.434   100.00     2    a(2470)      -                                      
    4.949    2.676     0.00     1    a(2471)      -                                      
    4.949    2.676     0.00     2    a(2471)      -                                      
    4.706    3.339    10.00     1    a(2471)      -                                      
    4.706    3.339    10.00     2    a(2471)      -                                      
    4.498    3.725    15.00     1    a(2471)      -                                      
    4.498    3.725    15.00     2    a(2471)      -                                      
    4.317    4.495    25.00     1    a(2471)     1.0                                     
    4.317    4.495    25.00     2    a(2471)     1.0                                     
    4.027    5.382    35.00     1    a(2471)      -                                      
    4.027    5.382    35.00     2    a(2471)      -                                      
    6.125    0.000    20.00     1    a(2472)      -                                      
    5.522    1.389    20.00     1    a(2472)      -                                      
    5.108    2.377    20.00     1    a(2472)      -                                      
    4.610    3.793    20.00     1    a(2472)      -                                      
    4.473    4.093    20.00     1    a(2472)      -                                      
    4.469    4.118    20.00     1    a(2472)      -                                      
    4.469    4.118    20.00     2    a(2472)      -                                      
    3.363    4.705    20.00     2    a(2472)      -                                      
    2.037    5.548    20.00     2    a(2472)      -                                      
    1.019    6.262    20.00     2    a(2472)      -                                      
    0.000    7.006    20.00     2    a(2472)      -                                      
    0.000   10.231    60.00     2    a(2472)      -                                      
    3.772    7.484    60.00     1    a(2472)      -                                      
    3.772    7.484    60.00     2    a(2472)      -                                      
    6.338    0.000    60.00     1    a(2472)      -                                      
    1.893    0.000    20.00    99    a(2473)      -                                      
    1.723    0.650    20.00    99    a(2473)      -                                      
    1.541    1.322    20.00    99    a(2473)      -                                      
    1.487    1.366    20.00    99    a(2473)      -                                      
    0.000    2.356    20.00    99    a(2473)      -                                      
    0.682    2.029    20.00    99    a(2473)      -                                      
    1.020    1.833    20.00    99    a(2473)      -                                      
    1.566    1.333    20.00    99    a(2473)      -                                      
    4.767    2.720     0.00     1       b         -      
    4.767    2.720     0.00     2       b         -      
    4.505    3.371    10.00     1       b         -      
    4.505    3.371    10.00     2       b         -      
    4.285    4.504    25.00     1       b        1.0     
    4.285    4.504    25.00     2       b        1.0     
    4.278    1.926   -25.10     0       c         -        
    4.278    1.926   -25.10     1       c         -        
    4.278    1.926   -25.10     2       c         -        
    0.000    8.717    40.00     2       d         -        
    1.845    6.904    40.00     2       d         -                                      
    3.683    5.822    40.00     2       d         -                                      
    3.683    5.822    40.00     1       d         -                                      
    4.409    3.859    40.00     1       d         -                                      
    5.143    2.317    40.00     1       d         -                                      
    6.361    0.000    40.00     1       d         -                                      
    0.000    2.695   -10.00     0       d         -                                      
    0.809    1.984   -10.00     0       d         -                                      
    1.864    0.931   -10.00     0       d         -                                      
    2.489    0.000   -10.00     0       d         -                                      
    0.000    4.821   -10.00     2       d         -                                      
    2.046    3.636   -10.00     2       d         -                                      
    3.591    3.026   -10.00     2       d         -                                      
    4.978    2.271   -10.00     2       d         -                                      
    4.978    2.271   -10.00     3       d         -                                      
    5.001    1.987   -10.00     3       d         -                                      
    5.413    1.106   -10.00     3       d         -                                      
    5.764    0.000   -10.00     3       d         -                                      
    0.000    3.455   -15.00     0       d         -                                      
    1.034    2.780   -15.00     0       d         -                                      
    2.113    1.630   -15.00     0       d         -                                      
    3.455    0.000   -15.00     0       d         -                                      
    0.000    4.674   -15.00     2       d         -                                      
    2.002    3.428   -15.00     2       d         -                                      
    3.496    2.783   -15.00     2       d         -                                      
    4.817    2.226   -15.00     2       d         -                                      
    4.817    2.226   -15.00     3       d         -                                      
    5.263    0.887   -15.00     3       d         -                                      
    5.492    0.000   -15.00     3       d         -                                      
    4.714    0.000   -20.00     0       d         -                                      
    3.812    1.077   -20.00     0       d         -                                      
    3.097    1.920   -20.00     0       d         -                                      
    2.614    2.448   -20.00     0       d         -                                      
    1.453    3.412   -20.00     0       d         -                                      
    1.453    3.412   -20.00     2       d         -                                      
    2.524    2.953   -20.00     2       d         -                                      
    4.008    2.535   -20.00     2       d         -                                      
    4.682    2.155   -20.00     2       d         -                                      
    4.682    2.155   -20.00     3       d         -                                      
    4.902    1.454   -20.00     3       d         -                                      
    5.108    0.751   -20.00     3       d         -                                      
    5.169    0.000   -20.00     3       d         -                                      
    4.477    2.023   -24.50     0       d         -                                      
    4.477    2.023   -24.50     1       d         -                                      
    4.477    2.023   -24.50     2       d         -                                      
    4.713    3.983    20.00     1       e         -       
    4.713    3.983    20.00     2       e         -       
    4.160    5.099    35.00     1       f         -       
    4.160    5.099    35.00     2       f         -       
    3.890    6.506    50.00     1       f         -       
    3.890    6.506    50.00     2       f         -       
    3.679    4.206    18.00     1       g         -      
    3.679    4.206    18.00     2       g         -      
    3.935    6.356    24.00     1       g         -      
    3.935    6.356    24.00     2       g         -      
    3.422    8.413    70.00     1       g         -      
    3.422    8.413    70.00     2       g         -

Notes and References

Prefix m denotes molality; t - experimental temperature (^oC); solid - identity of the solid which the solution is saturated with respect to; ref. - source of data; weight - the weight given to the data point in the fit of the model (normalised).
Solids: 0 = ice, 1 = NaCl(s), 2 = NH4Cl(s), 3 = NaCl.2H2O(s); 99 = not listed.
Sources: a - H. L. Silcock, Solubilities of Inorganic and Organic Compounds, Vol. 3, Pergamon, Oxford, 1979, (the table numbers are given in parentheses); b - U. Sborgi and C. Franco (1921) Gazz. Chim. Ital. 51, 1-57; c - D. Mazzotto (1891) Nuovo Cimento [3] 29, 21-36; d - Y. Hara, N. Akiyoshi, N. Nawachi, and H. Nakamura (1991) Kogyo Kayaku 52, 239-245; (1991); e - E. Rengade (1922) Chim. et Industr. 7, 298T-306T; f - E. Toporescu (1922) Comptes Rendus 175, 268-270; g - A. Krause (1927) Przemysl Chemiczny 11, 625-628.
Data from reference a(2466) were taken directly from the source paper (V. K. Semenchenko and E. A. Zavada (1931) Zh. Obshch. Khim. 1(8-9), 1114-1124), because Silcock lists only molar concentrations.

(2) Osmotic Coefficients from Isopiestic Measurements

    mNaCl     mNH4Cl     t      osm    ref.   weight                             
    5.4265    0.0000   25.0   1.2245    h      0.0      
    4.9653    0.5862   25.0   1.1969    h      1.0      
    4.5442    1.1205   25.0   1.1730    h      1.0      
    4.1044    1.6715   25.0   1.1504    h      1.0      
    3.6188    2.2875   25.0   1.1250    h      1.0      
    3.1326    2.9032   25.0   1.1009    h      1.0                                      
    2.5961    3.5718   25.0   1.0773    h      1.0                                      
    2.0514    4.2586   25.0   1.0531    h      1.0                                      
    1.4880    4.9676   25.0   1.0293    h      1.0                                      
    0.8893    5.7131   25.0   1.0064    h      1.0                                      
    0.0000    6.8293   25.0   0.9730    h      0.0                                      
    5.0525    0.0000   25.0   1.1958    h      0.0                                      
    4.6172    0.5451   25.0   1.1704    h      1.0                                      
    4.2165    1.0397   25.0   1.1495    h      1.0                                      
    3.8038    1.5491   25.0   1.1287    h      1.0                                      
    3.3468    2.1156   25.0   1.1061    h      1.0                                      
    2.8925    2.6807   25.0   1.0841    h      1.0                                      
    2.3928    3.2921   25.0   1.0628    h      1.0                                      
    1.8867    3.9168   25.0   1.0411    h      1.0                                      
    1.3660    4.5602   25.0   1.0195    h      1.0                                      
    0.8145    5.2322   25.0   0.9992    h      1.0                                      
    0.0000    6.2279   25.0   0.9701    h      0.0                                      
    4.3111    0.0000   25.0   1.1403    h      0.0                                      
    3.9605    0.4177   25.0   1.1228    h      1.0                                      
    3.6024    0.8500   25.0   1.1041    h      1.0                                      
    3.1171    1.4208   25.0   1.0833    h      1.0                                      
    2.7588    1.8492   25.0   1.0669    h      1.0                                      
    2.3447    2.3428   25.0   1.0487    h      1.0                                      
    1.8864    2.8857   25.0   1.0301    h      1.0                                      
    1.4296    3.4263   25.0   1.0124    h      1.0                                      
    0.9851    3.9550   25.0   0.9951    h      1.0                                      
    0.4603    4.5753   25.0   0.9762    h      1.0                                      
    0.0000    5.1149   25.0   0.9611    h      0.0                                      
    3.6890    0.0000   25.0   1.0957    h      0.0                                      
    3.3811    0.3566   25.0   1.0814    h      1.0                                      
    3.0652    0.7232   25.0   1.0670    h      1.0                                      
    2.6454    1.2058   25.0   1.0496    h      1.0                                      
    2.3356    1.5655   25.0   1.0361    h      1.0                                      
    1.9801    1.9785   25.0   1.0211    h      1.0                                      
    1.5880    2.4291   25.0   1.0062    h      1.0                                      
    1.2000    2.8761   25.0   0.9916    h      1.0                                      
    0.8242    3.3092   25.0   0.9779    h      1.0                                      
    0.3841    3.8182   25.0   0.9619    h      1.0                                      
    0.0000    4.2547   25.0   0.9500    h      0.0                                      
    3.1311    0.0000   25.0   1.0574    h      0.0                                      
    2.8622    0.3018   25.0   1.0464    h      1.0                                      
    2.5898    0.6111   25.0   1.0343    h      1.0                                      
    2.2295    1.0162   25.0   1.0201    h      1.0                                      
    1.9637    1.3163   25.0   1.0094    h      1.0                                      
    1.6619    1.6605   25.0   0.9965    h      1.0                                      
    1.3287    2.0326   25.0   0.9850    h      1.0                                      
    1.0017    2.4009   25.0   0.9730    h      1.0                                      
    0.6862    2.7553   25.0   0.9620    h      1.0                                      
    0.3188    3.1692   25.0   0.9492    h      1.0                                      
    0.0000    3.5261   25.0   0.9389    h      0.0                                      
    2.9022    0.0000   25.0   1.0423    h      0.0                                      
    2.6518    0.2797   25.0   1.0319    h      1.0                                      
    2.3981    0.5658   25.0   1.0206    h      1.0                                      
    2.0619    0.9399   25.0   1.0077    h      1.0                                      
    1.8139    1.2159   25.0   0.9984    h      1.0                                      
    1.5334    1.5321   25.0   0.9868    h      1.0                                      
    1.2249    1.8738   25.0   0.9762    h      1.0                                      
    0.9229    2.2121   25.0   0.9649    h      1.0                                      
    0.6316    2.5358   25.0   0.9550    h      1.0                                      
    0.2930    2.9129   25.0   0.9436    h      1.0                                      
    0.0000    3.2392   25.0   0.9339    h      0.0                                      
    2.5454    0.0000   25.0   1.0195    h      0.0                                      
    2.3245    0.2451   25.0   1.0099    h      1.0                                      
    2.0972    0.4948   25.0   1.0012    h      1.0                                      
    1.8004    0.8206   25.0   0.9901    h      1.0                                      
    1.5834    1.0614   25.0   0.9812    h      1.0                                      
    1.3369    1.3359   25.0   0.9709    h      1.0                                      
    1.0661    1.6309   25.0   0.9622    h      1.0                                      
    0.8016    1.9212   25.0   0.9531    h      1.0                                      
    0.5482    2.2008   25.0   0.9440    h      1.0                                      
    0.2540    2.5250   25.0   0.9338    h      1.0                                      
    0.0000    2.8026   25.0   0.9259    h      0.0                                      
    2.2644    0.0000   25.0   1.0023    h      0.0                                      
    2.0692    0.2182   25.0   0.9922    h      1.0                                      
    1.8615    0.4392   25.0   0.9865    h      1.0                                      
    1.5962    0.7276   25.0   0.9767    h      1.0                                      
    1.4023    0.9399   25.0   0.9690    h      1.0                                      
    1.1831    1.1821   25.0   0.9596    h      1.0                                      
    0.9425    1.4417   25.0   0.9519    h      1.0                                      
    0.7076    1.6961   25.0   0.9442    h      1.0                                      
    0.4832    1.9402   25.0   0.9365    h      1.0                                      
    0.2237    2.2235   25.0   0.9274    h      1.0                                      
    0.0000    2.4671   25.0   0.9199    h      0.0                                      
    1.0840    1.0830   25.0   0.9553    i      1.0    
    1.6830    1.6800   25.0   0.9992    i      1.0                                      
    2.2900    2.2920   25.0   1.0454    i      1.0                                      
    2.9550    2.9820   25.0   1.0981    i      0.0