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 7 of Clegg et al. (1998b). Fits of the model are described in section 3.9 of that paper. The following types of data were used:

1. Solubilities of the solid NaNO3(s) in the ternary solution.
2. Equilibrium vapour pressures of HNO3 and water.

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 a 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

    mHNO3     mNaNO3      t    solid   ref.      weight  
    0.000      8.793     0.00    1    a(414)       -     
    5.560      4.221     0.00    1    a(414)       -     
   12.790      0.959     0.00    1    a(414)       -     
   28.406      0.704     0.00    1    a(414)       -     
   45.017      0.729     0.00    1    a(414)       -     
  140.071      5.308     0.00    1    a(414)       -        
    0.000     10.132    20.00    1    a(414)       -           
    5.254      4.862    20.00    1    a(414)       -     
   12.589      1.380    20.00    1    a(414)       -     
   24.779      0.656    20.00    1    a(414)       -                
   43.970      0.905    20.00    1    a(414)       -                
  138.688      6.707    20.00    1    a(414)       -                
    0.0000    8.5663     0.00    1    a(412)       -     
    0.3401    8.1828     0.00    1    a(412)       -     
    0.7301    7.7622     0.00    1    a(412)       -     
    1.1230    7.2636     0.00    1    a(412)       -     
    1.6032    6.7351     0.00    1    a(412)       -     
    2.1473    6.1944     0.00    1    a(412)       -     
    3.4421    5.0393     0.00    1    a(412)       -     
    4.1199    4.4862     0.00    1    a(412)       -     
    4.7613    3.9779     0.00    1    a(412)       -     
    6.2092    3.0425     0.00    1    a(412)       -     
    7.5172    2.3657     0.00    1    a(412)       -     
    9.6815    1.7591     0.00    1    a(412)       -     
    0.000     9.783     15.00    1    a(413)       -     
    2.622     6.752     15.00    1    a(413)       -     
    3.557     5.883     15.00    1    a(413)       -     
    7.852     2.982     15.00    1    a(413)       -     
   17.411     1.299     15.00    1    a(413)       -     
   31.161     0.894     15.00    1    a(413)       -     
   51.250     1.171     15.00    1    a(413)       -     
   82.299     2.640     15.00    1    a(413)       -     
  130.656     5.597     15.00    1    a(413)       -     
  488.679    31.645     15.00    1    a(413)       -     
    0.000    16.449     75.00    1    a(413)       -     
    6.162    10.225     75.00    1    a(413)       -     
   11.026     6.861     75.00    1    a(413)       -     
   14.257     5.479     75.00    1    a(413)       -     
   16.101     4.924     75.00    1    a(413)       -     
   34.268     2.712     75.00    1    a(413)       -     
   48.851     3.172     75.00    1    a(413)       -     
   78.646     4.393     75.00    1    a(413)       -     
  246.548    15.547     75.00    1    a(413)       -     
  302.560    19.694     75.00    1    a(413)       -     
  470.273    31.767     75.00    1    a(413)       -     
   82.9524    2.7105    25.00    1       b        0.0      
   56.6907    1.4548    25.00    1       b        0.0    
   27.6785    1.0957    25.00    1       b        1.0      
   23.9785    1.1941    25.00    1       b        1.0      
   10.5254    2.5799    25.00    1       b        1.0      
    9.0845    3.1004    25.00    1       b        1.0     
    5.6447    4.9441    25.00    1       b        1.0    
    4.3094    6.0754    25.00    1       b        1.0    
    1.8608    8.6180    25.00    1       b        1.0    
    0.0000    0.6676    25.00    1       b        1.0    
   18.5236    3.6022    65.00    1       b         -     
   16.2147    4.0461    65.00    1       b         -     
   12.7217    5.1356    65.00    1       b         -     
   10.8440    6.0373    65.00    1       b         -     
    5.0321    9.9374    65.00    1       b         -     
    1.8381    2.8108    65.00    1       b         -     
    0.0000    4.9159    65.00    1       b         -     
    7.53      1.116     46.40    1       b         -     
    7.53      1.116     46.40    0       b         -     
    7.53      1.116     46.40    2       b         -     
    0.0000    1.8126    35.00    1       c         -     
    2.0646    9.2129    35.00    1       c         -     
    3.2592    7.7646    35.00    1       c         -     
    3.7677    6.5225    35.00    1       c         -     
    4.9685    5.8923    35.00    1       c         -     
    5.6561    5.2517    35.00    1       c         -     
    6.6146    4.6797    35.00    1       c         -     
    8.8982    3.8869    35.00    1       c         -     
   10.3106    3.7965    35.00    1       c         -     
   16.7080    2.1803    35.00    1       c         -     
   22.1597    1.6599    35.00    1       c         -     
   32.2631    1.6424    35.00    1       c         -     
   37.3698    1.4528    35.00    1       c         -     
   54.1968    1.9008    35.00    1       c         -     
   85.6881    3.5643    35.00    1       c         -     
  170.7981    8.6770    35.00    1       c         -     
    0.0000    3.1349    45.00    1       c         -     
    1.6394    1.3278    45.00    1       c         -     
    2.8016    9.2360    45.00    1       c         -     
    4.3995    8.2707    45.00    1       c         -     
    6.7351    6.4656    45.00    1       c         -     
    9.8908    4.4798    45.00    1       c         -     
    9.9420    4.3524    45.00    1       c         -     
   13.9906    3.2845    45.00    1       c         -     
   13.6141    2.9160    45.00    1       c         -     
   18.9376    2.2745    45.00    1       c         -     
   29.5320    1.9176    45.00    1       c         -     
   54.0779    2.0877    45.00    1       c         -     
   82.8673    3.2971    45.00    1       c         -     
  132.772     6.2904    45.00    1       c         -     
  135.678     0.6668    45.00    1       c         -     
   83.0544    2.7625    25.00    1       d        0.0    
   57.0008    1.4991    25.00    1       d        0.0    
   27.7011    1.1127    25.00    1       d        1.0    
   23.9934    1.2058    25.00    1       d        1.0    
   10.5410    2.5894    25.00    1       d        1.0    
    9.0976    3.1214    25.00    1       d        1.0    
    5.3640    4.1117    25.00    1       d        0.0    
    4.3227    6.0997    25.00    1       d        1.0    
    1.8593    8.6319    25.00    1       d        1.0    
    0.8274    9.7658    25.00    1       d        1.0    
    0.0000   10.7650    25.00    1       d        1.0    
   18.5199    3.6123    65.00    1       d         -     
   16.2531    4.0453    65.00    1       d         -     
   12.7299    5.1296    65.00    1       d         -     
   10.8577    6.0430    65.00    1       d         -     
    5.0460    9.9598    65.00    1       d         -     
    1.8795   13.1325    65.00    1       d         -     
    0.0000   14.9499    65.00    1       d         -     
    0.0000    7.2325   -18.10    1       d         -     
    0.0000    7.2325   -18.10    0       d         -     
    0.1337    7.1980   -18.30    1       d         -     
    0.1337    7.1980   -18.30    0       d         -     
    0.5394    7.0592   -18.90    1       d         -     
    0.5394    7.0592   -18.90    0       d         -     
    2.1683    6.4977   -22.00    1       d         -     
    2.1683    6.4977   -22.00    0       d         -     
    4.3098    6.0603   -27.10    1       d         -     
    4.3098    6.0603   -27.10    0       d         -     
    6.9078    5.2163   -43.90    1       d         -     
    6.9078    5.2163   -43.90    0       d         -     
    7.7516    4.9451   -46.40    1       d         -     
    7.7516    4.9451   -46.40    0       d         -     
    8.7177    4.6659   -44.70    1       d         -     
    8.7177    4.6659   -44.70    2       d         -     
   12.6043    3.4679   -28.80    1       d         -     
   12.6043    3.4679   -28.80    2       d         -     
   20.1545    1.1331   -21.20    1       d         -     
   20.1545    1.1331   -21.20    2       d         -     
    0.0000    7.2325   -18.10    1       d         -     
    0.0000    7.2325   -18.10    0       d         -     
    0.0333    7.1772   -18.15    1       d         -     
    0.0333    7.1772   -18.15    0       d         -     
    0.0435    7.1696   -18.16    1       d         -     
    0.0435    7.1696   -18.16    0       d         -     
    0.0817    7.1108   -18.21    1       d         -     
    0.0817    7.1108   -18.21    0       d         -     
    0.1652    6.9579   -18.32    1       d         -     
    0.1652    6.9579   -18.32    0       d         -     
    0.4053    6.7137   -18.59    1       d         -     
    0.4053    6.7137   -18.59    0       d         -     
    0.8133    6.1832   -19.20    1       d         -     
    0.8133    6.1832   -19.20    0       d         -     
    1.0030    5.8974   -19.63    1       d         -     
    1.0030    5.8974   -19.63    0       d         -     
    1.7882    4.9706   -21.30    1       d         -     
    1.7882    4.9706   -21.30    0       d         -     
    3.1507    3.5011   -25.30    1       d         -     
    3.1507    3.5011   -25.30    0       d         -     
    7.5410    1.1255   -46.40    1       d         -     
    7.5410    1.1255   -46.40    0       d         -     
    7.5410    1.1255   -46.40    2       d         -     

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 = NaNO3(s), 2 = HNO3.3H2O(s). The solids for data from sources a(412) and a(414) are assumed to be NaNO3(s).
• Sources: a - H. L. Silcock, Solubilities of Inorganic and Organic Compounds, Vol. 3, Pergamon, Oxford, 1979, (the table numbers are given in parentheses); b - Gmelin Handbook of Inorganic Chemistry, Vol. "Sodium" (System 21), Verlag Chemie, Weinheim, 1966; c - Ky Tu and Ngoc The Luong (1977) Tap Chi Hoa Hoc 15, 1-5; d - N. S. Kurnakov and V. I. Nikolaev (1927) Z. Phys. Chem. (Leipzig) 130, 193-204.

(2) Vapour Pressure Measurements

   mHNO3     mNaNO3       t     aW     gamma   ref.   weight     
   16.087     1.007     25.00  0.4007            e     1.0       
   19.538     1.116     25.00  0.3317            e     1.0       
   23.745     1.248     25.00  0.2622            e     1.0       
   16.087     1.007     25.00          2.158     e     7.5E-5    
   19.538     1.116     25.00          2.570     e     7.5E-5    
   23.745     1.248     25.00          2.612     e     7.5E-5    

Notes and References

• Prefix m denotes molality; t - experimental temperature (^oC); aW - water activity; gamma - mean molal activity coefficient of HNO3; ref. - source of data; weight - the weight given to the data point in the fit of the model (normalised).
• Source: e - R. Flatt and F. Benguerel (1962) Helv. Chim. Acta 45, 1772-1776.
• The experimental vapour pressures have been used to calculate aW and gamma, using standard thermodynamic relationships (including the Henry's law constant for HNO3 given in section 2.2 of Clegg et al. (1998b)).