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 12 of Clegg et al. (1998b). Fits of the model are described in section 3.14 of that paper. The following types of data were considered:

Solubilities of the solids Na2SO4(s), Na2SO4.10H2O(s), (NH4)2SO4(s), and (NH4)2SO4.Na2SO4.4H2O(s) in the ternary solutions.
Osmotic coefficients from isopiestic measurements.
Osmotic coefficients from water activity measurements (not fitted).

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

  mNa2SO4    m(NH4)2SO4       t      solid      ref.      weight     
   0.3719     4.8052       -19.5       0      a(2288)      -         
   0.3719     4.8052       -19.5      10      a(2288)      -         
   0.3719     4.8052       -19.5       2      a(2288)      -         
   0.3805     4.8047       -18.0      10      a(2288)      -         
   0.3805     4.8047       -18.0       2      a(2288)      -         
   0.3746     4.8131       -16.0      10      a(2288)      -         
   0.3746     4.8131       -16.0       2      a(2288)      -         
   0.3746     4.8131       -16.0       3      a(2288)      -         
   0.3999     4.9103       -13.0       2      a(2288)      -         
   0.3999     4.9103       -13.0       3      a(2288)      -         
   0.4454     4.9634       -10.0       2      a(2288)      -         
   0.4454     4.9634       -10.0       3      a(2288)      -         
   0.5505     5.0480         0.0       2      a(2288)      -         
   0.5505     5.0480         0.0       3      a(2288)      -         
   0.7635     5.2671        15.0       2      a(2288)      -         
   0.7635     5.2671        15.0       3      a(2288)      -         
   1.0284     5.3727        25.0       2      a(2288)     0.375      
   1.0284     5.3727        25.0       3      a(2288)     0.00125    
   1.3864     5.6827         -         2      a(2288)      -         
   1.3864     5.6827         -         3      a(2288)      -         
   1.8148     5.7578        50.0       2      a(2288)      -         
   1.8148     5.7578        50.0       3      a(2288)      -         
   0.4591     4.4331       -13.0      10      a(2288)      -         
   0.4591     4.4331       -13.0       3      a(2288)      -         
   0.5480     4.2454       -10.0      10      a(2288)      -         
   0.5480     4.2454       -10.0       3      a(2288)      -                      
   0.8489     3.5265         0.0      10      a(2288)      -                      
   0.8489     3.5265         0.0       3      a(2288)      -                      
   1.6119     2.5188        15.0      10      a(2288)      -                      
   1.6119     2.5188        15.0       3      a(2288)      -                      
   2.2162     2.1857        20.0      10      a(2288)      -                      
   2.2162     2.1857        20.0       3      a(2288)      -                      
   2.8788     1.6712        25.0      10      a(2288)     1.0        
   2.8788     1.6712        25.0       3      a(2288)     0.00125    
   3.1809     1.5883        26.5      10      a(2288)      -         
   3.1809     1.5883        26.5       3      a(2288)      -         
   3.1809     1.5883        26.5       1      a(2288)      -         
   2.9354     2.1715        35.0       1      a(2288)      -         
   2.9354     2.1715        35.0       3      a(2288)      -         
   2.8500     2.6248        40.0       1      a(2288)      -         
   2.8500     2.6248        40.0       3      a(2288)      -         
   2.6190     3.8210        50.0       1      a(2288)      -         
   2.6190     3.8210        50.0       3      a(2288)      -         
   2.5340     4.6913        55.0       1      a(2288)      -         
   2.5340     4.6913        55.0       3      a(2288)      -         
   2.3154     2.3071        25.0       3      a(2288)     0.00125    
   2.6249     2.6251        35.0       3      a(2288)      -         
   2.4130     5.8790        54.3       3      a(2288)      -         
   2.4130     5.8790        54.3       1      a(2288)      -         
   2.4130     5.8790        54.3       2      a(2288)      -         
   2.5391     6.3759        75.0       1      a(2288)      -         
   2.5391     6.3759        75.0       2      a(2288)      -         
   2.6676     7.1891       100.0       1      a(2288)      -         
   2.6676     7.1891       100.0       2      a(2288)      -         
   0.5054     1.2551         0.0      10      a(2292)      -         
   1.9742     0.0000        25.0      10      a(2292)     1.0        
   2.3036     0.6753        25.0      10      a(2292)     1.0        
   2.8828     1.6791        25.0      10      a(2292)     1.0        
   2.8828     1.6791        25.0       3      a(2292)     0.00125    
   1.6641     3.1523        25.0       3      a(2292)     0.00125    
   1.0338     5.3877        25.0       3      a(2292)     0.00125    
   1.0338     5.3877        25.0       2      a(2292)     0.375      
   0.0000     5.8031        25.0       2      a(2292)     0.375      
   2.0063     3.5062        60.0       1      a(2292)      -         
   2.0063     3.5062        60.0       2      a(2292)      -         
   2.4977     6.5277        80.0       1      a(2292)      -         
   2.4977     6.5277        80.0       2      a(2292)      -         
   0.0000     5.5618        15.0       2      a(2293)      -         
   0.2020     5.5342        15.0       2      a(2293)      -         
   0.2774     5.5072        15.0       2      a(2293)      -         
   0.3697     5.4602        15.0       2      a(2293)      -         
   0.5490     5.3779        15.0       2      a(2293)      -         
   0.8977     5.2723        15.0       2      a(2293)      -         
   0.8977     5.2723        15.0       3      a(2293)      -         
   0.9896     4.9189        15.0       3      a(2293)      -         
   1.1584     4.1303        15.0       3      a(2293)      -         
   1.3069     3.7061        15.0       3      a(2293)      -         
   1.4942     3.2000        15.0       3      a(2293)      -         
   1.6097     2.7931        15.0       3      a(2293)      -         
   1.7221     2.5936        15.0       3      a(2293)      -         
   1.7901     2.5645        15.0       3      a(2293)      -         
   1.8500     2.4810        15.0       3      a(2293)      -         
   1.8500     2.4810        15.0      10      a(2293)      -         
   1.6128     2.3414        15.0      10      a(2293)      -         
   1.2686     0.9071        15.0      10      a(2293)      -         
   0.9329     0.0000        15.0      10      a(2293)      -         
   0.0000     6.1100        35.0       2      a(2293)      -         
   0.4918     5.9260        35.0       2      a(2293)      -         
   0.9714     5.8306        35.0       2      a(2293)      -         
   1.3134     5.6050        35.0       2      a(2293)      -         
   1.4168     5.5389        35.0       2      a(2293)      -         
   1.4168     5.5389        35.0       3      a(2293)      -         
   1.6624     4.2444        35.0       3      a(2293)      -         
   1.9101     3.6770        35.0       3      a(2293)      -         
   2.0288     3.3969        35.0       3      a(2293)      -         
   2.1432     3.2104        35.0       3      a(2293)      -         
   2.5761     2.6574        35.0       3      a(2293)      -         
   2.7568     2.4319        35.0       3      a(2293)      -         
   2.9641     2.3256        35.0       3      a(2293)      -         
   2.9641     2.3256        35.0       1      a(2293)      -         
   3.0517     2.0158        35.0       1      a(2293)      -         
   3.1780     1.4837        35.0       1      a(2293)      -         
   3.2381     1.0794        35.0       1      a(2293)      -         
   3.3532     0.5228        35.0       1      a(2293)      -         
   3.4881     0.0000        35.0       1      a(2293)      -         
   1.9523     0.0000        25.0      10      a(2294)     1.0        
   2.1652     0.7908        25.0      10      a(2294)     0.0        
   2.7379     1.5016        25.0      10      a(2294)     1.0        
   3.0157     1.7744        25.0      10      a(2294)     1.0        
   3.0157     1.7744        25.0       3      a(2294)     0.00125    
   2.7905     1.9830        25.0       3      a(2294)     0.00125    
   1.7005     3.5497        25.0       3      a(2294)     0.00125    
   1.0491     5.4899        25.0       3      a(2294)     0.00125    
   1.0491     5.4899        25.0       2      a(2294)     0.375      
   0.8640     5.4690        25.0       2      a(2294)     0.375      
   0.4256     5.6303        25.0       2      a(2294)     0.375      
   0.0000     5.8031        25.0       2      a(2294)     0.375      
   3.1927     0.0000        60.0       1      a(2294)      -         
   2.9935     1.1586        60.0       1      a(2294)      -         
   2.5406     4.3054        60.0       1      a(2294)      -         
   2.4587     5.9739        60.0       1      a(2294)      -         
   2.4587     5.9739        60.0       2      a(2294)      -         
   1.5374     6.2244        60.0       2      a(2294)      -         
   0.0000     6.6576        60.0       2      a(2294)      -         
   3.1103     1.7866        28.5       1      a(2294)      -         
   3.1103     1.7866        28.5       3      a(2294)      -         
   2.3940     2.4238        28.6       3      a(2294)      -         
   3.1437     2.2375        38.0       3      a(2294)      -         
   1.6180     5.6731        44.5       3      a(2294)      -         
   1.6180     5.6731        44.5       2      a(2294)      -         
   2.8223     3.0886        45.0       1      a(2294)      -         
   2.8223     3.0886        45.0       3      a(2294)      -         
   2.5198     4.9661        55.4       1      a(2294)      -         
   2.5198     4.9661        55.4       3      a(2294)      -         
   2.1902     5.8575        55.4       3      a(2294)      -         
   2.1902     5.8575        55.4       2      a(2294)      -         
     -           -          59.0       1      a(2294)      -         
     -           -          59.0       2      a(2294)      -         
     -           -          59.0       3      a(2294)      -         
   2.4208     6.0528        63.4       1      a(2294)      -         
   2.4208     6.0528        63.4       2      a(2294)      -         
   2.7095     7.4319       100.0       1      a(2294)      -         
   2.7095     7.4319       100.0       2      a(2294)      -         
   2.8297     7.9713       111.0       1      a(2294)      -         
   2.8297     7.9713       111.0       2      a(2294)      -         
   0.8705     3.5549         0.0      10      a(2295)      -         
   0.8705     3.5549         0.0       3      a(2295)      -         
   0.5594     5.0754         0.0       3      a(2295)      -         
   0.5594     5.0754         0.0       2      a(2295)      -         
   1.0228     3.3092         0.0      10      a(2295)      -         
   1.0228     3.3092         0.0       3      a(2295)      -         
   0.6105     5.1139         4.6       3      a(2295)      -         
   0.6105     5.1139         4.6       2      a(2295)      -         
   1.3465     2.8971        10.4      10      a(2295)      -         
   1.3465     2.8971        10.4       3      a(2295)      -         
   0.8072     5.2944        14.5       3      a(2295)      -         
   0.8072     5.2944        14.5       2      a(2295)      -         
   1.9513     2.3548        18.5      10      a(2295)      -         
   1.9513     2.3548        18.5       3      a(2295)      -         
   2.8493     1.8350        25.9      10      a(2295)      -         
   2.8493     1.8350        25.9       3      a(2295)      -         
      -          -          26.3      10      a(2295)      -         
      -          -          26.3       1      a(2295)      -         
      -          -          26.3       3      a(2295)      -         
   1.0731     5.4668        28.4       3      a(2295)      -         
   1.0731     5.4668        28.4       2      a(2295)      -         
   0.5457     0.7869         0.0      10      a(2299)      -         
   0.6296     1.6210         0.0      10      a(2299)      -         
   0.7333     2.5613         0.0      10      a(2299)      -         
   0.8461     3.3958         0.0      10      a(2299)      -         
   0.8461     3.3958         0.0       3      a(2299)      -         
   0.8105     3.5774         0.0       3      a(2299)      -         
   0.7084     3.7004         0.0       3      a(2299)      -         
   0.6383     4.1749         0.0       3      a(2299)      -         
   0.5403     4.9606         0.0       3      a(2299)      -         
   0.5403     4.9606         0.0       2      a(2299)      -         
   0.3629     5.0454         0.0       2      a(2299)      -         
   0.1857     5.1936         0.0       2      a(2299)      -         
   0.5750     0.0000         7.0      10      a(2299)      -         
   0.7624     1.0324         7.0      10      a(2299)      -         
   0.9559     2.0636         7.0      10      a(2299)      -         
   1.1729     3.0651         7.0      10      a(2299)      -         
   1.1729     3.0651         7.0       3      a(2299)      -         
   0.9675     3.5985         7.0       3      a(2299)      -         
   0.8077     4.2939         7.0       3      a(2299)      -         
   0.6999     5.0436         7.0       3      a(2299)      -         
   0.6999     5.0436         7.0       2      a(2299)      -         
   0.0000     5.4803         7.0       2      a(2299)      -         
   0.3905     1.2777        -5.0      10      a(2299)      -                         
   0.3905     1.2777        -5.0       0      a(2299)      -                         
   0.6989     4.0367        -5.0      10      a(2299)      -                         
   0.6989     4.0367        -5.0       3      a(2299)      -                        
   0.4977     5.0087        -5.0       3      a(2299)      -                       
   0.4977     5.0087        -5.0       2      a(2299)      -                       
   0.0000     5.2158        -5.0       2      a(2299)      -              
   0.0000     1.3355        -5.0       2      a(2299)      -         
   0.0000     1.3355        -5.0       0      a(2299)      -         
   3.2806     0.9125         0.0      10      a(2300)      -                                    
   3.2806     0.9125         0.0       3      a(2300)      -                                    
   4.6953     0.5903         0.0       3      a(2300)      -                                    
   4.6953     0.5903         0.0       2      a(2300)      -                                    
   1.6321     3.1291        25.0      10      a(2300)     0.0                                   
   1.6321     3.1291        25.0       3      a(2300)     0.0                                   
   5.0270     1.0822        25.0       3      a(2300)     0.0                                   
   5.0270     1.0822        25.0       2      a(2300)     0.0                                   
   2.3656     3.0304        40.0       1      a(2300)      -                                    
   2.3656     3.0304        40.0       3      a(2300)      -                                    
   5.2406     1.5224        40.0       3      a(2300)      -                                    
   5.2406     1.5224        40.0       2      a(2300)      -                                    
   5.4289     2.6065        60.0       1      a(2300)      -                                    
   5.4289     2.6065        60.0       2      a(2300)      -                                    
   3.4850     0.0000        25.0       1      a(2301)     0.0        
   3.5689     0.2209        25.0       1      a(2301)     0.0        
   3.5208     0.5300        25.0       1      a(2301)     0.0        
   3.4246     0.9161        25.0       1      a(2301)     0.0        
   3.2612     1.3575        25.0       1      a(2301)     0.0        
   3.1083     2.0011        25.0       1      a(2301)     0.0        
   3.1083     2.0011        25.0       3      a(2301)     0.00125    
   3.1071     2.0024        25.0       1      a(2301)     0.0        
   3.1071     2.0024        25.0       3      a(2301)     0.00125    
   3.1107     1.9985        25.0       1      a(2301)     0.0        
   3.1107     1.9985        25.0       3      a(2301)     0.00125    
   3.0639     1.9635        25.0       1      a(2301)     0.0        
   3.0639     1.9635        25.0       3      a(2301)     0.00125    
   2.9486     2.1993        25.0       3      a(2301)     0.00125    
   2.2502     2.6708        25.0       3      a(2301)     0.00125    
   2.2011     3.2691        25.0       3      a(2301)     0.00125    
   1.8368     4.0276        25.0       3      a(2301)     0.00125    
   1.6872     4.5584        25.0       3      a(2301)     0.00125    
   1.5162     4.9745        25.0       3      a(2301)     0.00125    
   1.4237     5.1379        25.0       3      a(2301)     0.00125    
   1.4237     5.1379        25.0       2      a(2301)     0.375      
   0.9284     5.4905        25.0       2      a(2301)     0.375      
   0.6326     5.4896        25.0       2      a(2301)     0.375      
   0.5106     5.6733        25.0       2      a(2301)     0.375      
   0.0000     5.9705        25.0       2      a(2301)     0.375      
   0.3719    48.1538       -16.32     10      a(2298)      -         
   0.3719    48.1538       -16.32      2      a(2298)      -         
   0.0000    50.6517       -16.32      2      a(2298)      -         
   0.5179    43.0914       -11.02     10      a(2298)      -         
   0.5179    43.0914       -11.02      3      a(2298)      -         
   0.4302    21.6317       -11.02      3      a(2298)      -         
   0.4302    21.6317       -11.02      2      a(2298)      -         
   0.0000    51.4843       -11.02      2      a(2298)      -         
   0.4291    44.9842       -10.0      10      a(2298)      -         
   0.4291    44.9842       -10.0       3      a(2298)      -         
   0.3841    48.9975       -10.0       3      a(2298)      -         
   0.3841    48.9975       -10.0       2      a(2298)      -         
   0.0000    51.3455       -10.0       2      a(2298)      -         
   0.6478     0.0000        10.0      10      a(2298)      -         
   1.3600    28.7535        10.0      10      a(2298)      -         
   1.3600    28.7535        10.0       3      a(2298)      -         
   0.6939    51.6231        10.0       3      a(2298)      -         
   0.6939    51.6231        10.0       2      a(2298)      -         
   0.0000    55.2478        10.0       2      a(2298)      -         
   3.4782     0.0000        35.0       1      a(2298)      -         
   1.2906    55.7862        35.0       3      a(2298)      -         
   1.2906    55.7862        35.0       2      a(2298)      -         
   0.0000    60.0049        35.0       2      a(2298)      -         
   3.4415     0.0000        38.7       1      a(2298)      -         
   2.8709    25.1010        38.7       1      a(2298)      -         
   2.8709    25.1010        38.7       3      a(2298)      -         
   1.3566    56.5744        38.7       3      a(2298)      -         
   1.3566    56.5744        38.7       2      a(2298)      -         
   0.0000    60.7820        38.7       2      a(2298)      -         
   3.3488     0.0000        45.0       1      a(2296)      -         
   2.7754     3.1640        45.0       1      a(2296)      -         
   2.7754     3.1640        45.0       3      a(2296)      -         
   1.6014     5.7174        45.0       3      a(2296)      -         
   1.6014     5.7174        45.0       2      a(2296)      -         
   0.0000     6.2447        45.0       2      a(2296)      -         
   3.2484     0.0000        55.0       1      a(2296)      -         
   2.1648     5.8284        55.0       3      a(2296)      -         
   2.1648     5.8284        55.0       2      a(2296)      -         
   0.0000     6.5195        55.0       2      a(2296)      -         
   3.2334     0.0000        55.7       1      a(2296)      -         
   2.5118     4.8892        55.7       1      a(2296)      -         
   2.5118     4.8892        55.7       3      a(2296)      -         
   2.1926     5.8367        55.7       3      a(2296)      -         
   2.1926     5.8367        55.7       2      a(2296)      -         
   0.0000     6.5539        55.7       2      a(2296)      -         
   9.2200     0.0000        15.0      10      a(2291)      -         
  17.5074    25.0566        15.0      10      a(2291)      -         
  17.5074    25.0566        15.0       3      a(2291)      -         
   7.6269    52.6555        15.0       3      a(2291)      -         
   7.6269    52.6555        15.0       2      a(2291)      -         
   0.0000    55.7862        15.0       2      a(2291)      -         
  28.8701     0.0000        30.0      10      a(2291)      -         
  34.2100     7.6324        30.0      10      a(2291)      -         
  34.2100     7.6324        30.0       1      a(2291)      -         
  30.6963    18.4178        30.0       1      a(2291)      -         
  30.6963    18.4178        30.0       3      a(2291)      -         
  11.2183    54.8037        30.0       3      a(2291)      -         
  11.2183    54.8037        30.0       2      a(2291)      -         
   0.0000    58.9502        30.0       2      a(2291)      -         
  33.8658     0.0000        40.0       1      a(2291)      -         
  28.4760    26.2556        40.0       1      a(2291)      -         
  28.4760    26.2556        40.0       3      a(2291)      -         
  13.8772    56.8409        40.0       3      a(2291)      -         
  13.8772    56.8409        40.0       2      a(2291)      -         
   0.0000    61.3926        40.0       2      a(2291)      -         
   0.3724     4.8057       -19.5      10      a(2290)      -         
   0.3724     4.8057       -19.5       2      a(2290)      -         
   0.3724     4.8057       -19.5       0      a(2290)      -         
   0.3802     4.8057       -18.0      10      a(2290)      -         
   0.3802     4.8057       -18.0       2      a(2290)      -         
   0.3746     4.8133       -16.0      10      a(2290)      -         
   0.3746     4.8133       -16.0       3      a(2290)      -         
   0.3746     4.8133       -16.0       2      a(2290)      -         
   0.4154     3.8673       -15.0      10      a(2290)      -         
   0.4154     3.8673       -15.0       0      a(2290)      -         
   0.4182     4.2154       -15.0      10      a(2290)      -         
   0.3999     4.6619       -15.0      10      a(2290)      -         
   0.3999     4.6619       -15.0       3      a(2290)      -         
   0.4590     4.4349       -13.0      10      a(2290)      -         
   0.4590     4.4349       -13.0       3      a(2290)      -         
   0.3999     4.9117       -13.0       3      a(2290)      -         
   0.3999     4.9117       -13.0       2      a(2290)      -         
   0.4062     2.6186       -10.0      10      a(2290)      -         
   0.4062     2.6186       -10.0       0      a(2290)      -         
   0.4414     2.8834       -10.0      10      a(2290)      -         
   0.4724     3.3527       -10.0      10      a(2290)      -         
   0.5477     4.2457       -10.0      10      a(2290)      -         
   0.5477     4.2457       -10.0       3      a(2290)      -         
   0.4457     4.9647       -10.0       3      a(2290)      -         
   0.4457     4.9647       -10.0       2      a(2290)      -         
   0.8484     3.5267         0.0      10      a(2290)      -         
   0.8484     3.5267         0.0       3      a(2290)      -         
   0.5499     5.0479         0.0       3      a(2290)      -         
   0.5499     5.0479         0.0       2      a(2290)      -         
   1.6123     2.5202        15.0      10      a(2290)      -         
   1.6123     2.5202        15.0       3      a(2290)      -         
   0.7639     5.2674        15.0       3      a(2290)      -         
   0.7639     5.2674        15.0       2      a(2290)      -         
   2.2177     2.1872        20.0      10      a(2290)      -         
   2.2177     2.1872        20.0       3      a(2290)      -         
   2.8795     1.6725        25.0      10      a(2290)     1.0        
   2.8795     1.6725        25.0       3      a(2290)     0.00125    
   2.3163     2.3083        25.0       3      a(2290)     0.00125    
   1.0279     5.3733        25.0       3      a(2290)     0.00125    
   1.0279     5.3733        25.0       2      a(2290)     0.375      
   3.1823     1.5893        26.5      10      a(2290)      -         
   3.1823     1.5893        26.5       1      a(2290)      -         
   3.1823     1.5893        26.5       3      a(2290)      -         
   2.9359     2.1720        35.0       1      a(2290)      -         
   2.9359     2.1720        35.0       3      a(2290)      -         
   2.8514     2.6261        40.0       1      a(2290)      -         
   2.8514     2.6261        40.0       3      a(2290)      -         
   1.3870     5.6836        40.0       3      a(2290)      -         
   1.3870     5.6836        40.0       2      a(2290)      -         
   2.6190     3.8219        50.0       1      a(2290)      -         
   2.6190     3.8219        50.0       3      a(2290)      -         
   1.8164     5.7593        50.0       3      a(2290)      -         
   1.8164     5.7593        50.0       2      a(2290)      -         
   2.5346     4.6922        55.0       1      a(2290)      -         
   2.5346     4.6922        55.0       3      a(2290)      -         
   2.4149     5.8804        59.3       1      a(2290)      -         
   2.4149     5.8804        59.3       3      a(2290)      -         
   2.4149     5.8804        59.3       2      a(2290)      -         
   2.5416     6.3799        75.0       1      a(2290)      -         
   2.5416     6.3799        75.0       2      a(2290)      -         
   2.6683     7.1897       100.0       1      a(2290)      -         
   2.6683     7.1897       100.0       2      a(2290)      -         
   0.2808     0.0000        -1.2       0      a(2289)      -         
   0.2808     0.0000        -1.2      10      a(2289)      -         
   0.3324     4.6541       -21.0      10      a(2289)      -         
   0.3324     4.6541       -21.0       2      a(2289)      -         
   0.3324     4.6541       -21.0       0      a(2289)      -         
   0.0000     4.5433       -18.0       2      a(2289)      -         
   0.0000     4.5433       -18.0       0      a(2289)      -         
   3.2027     1.5806        26.0      10      a(2289)      -         
   3.2027     1.5806        26.0       1      a(2289)      -         
   3.2027     1.5806        26.0       3      a(2289)      -         
   3.5274     0.0000        32.3      10      a(2289)      -         
   3.5274     0.0000        32.3       1      a(2289)      -         
   0.5071     4.7644       -13.0      10      a(2289)      -         
   0.5071     4.7644       -13.0       3      a(2289)      -         
   0.8204     3.4675         1.0      10      a(2289)      -         
   0.8204     3.4675         1.0       3      a(2289)      -         
   1.7095     2.5738        14.0      10      a(2289)      -         
   1.7095     2.5738        14.0       3      a(2289)      -         
   2.0883     2.2980        19.0      10      a(2289)      -         
   2.0883     2.2980        19.0       3      a(2289)      -         
   3.1379     1.6773        25.5      10      a(2289)      -         
   3.1379     1.6773        25.5       3      a(2289)      -         
   3.0849     1.7630        29.0       1      a(2289)      -         
   3.0849     1.7630        29.0       3      a(2289)      -         
   3.0337     2.1056        33.5       1      a(2289)      -         
   3.0337     2.1056        33.5       3      a(2289)      -         
   2.9189     2.5460        38.5       1      a(2289)      -         
   2.9189     2.5460        38.5       3      a(2289)      -         
   2.7606     3.3190        46.0       1      a(2289)      -         
   2.7606     3.3190        46.0       3      a(2289)      -         
   2.5169     5.1622        58.0       1      a(2289)      -         
   2.5169     5.1622        58.0       3      a(2289)      -         
   2.4839     5.7606        59.0       1      a(2289)      -         
   2.4839     5.7606        59.0       2      a(2289)      -         
   2.4839     5.7606        59.0       3      a(2289)      -         
   2.5065     5.8541        62.5       1      a(2289)      -         
   2.5065     5.8541        62.5       3      a(2289)      -         
   2.4252     6.2859        79.0       1      a(2289)      -         
   2.4252     6.2859        79.0       3      a(2289)      -         
   1.2860     2.8896        10.0      10      a(2289)      -         
   1.2860     2.8896        10.0       2      a(2289)      -         
   1.4194     2.7761        11.0      10      a(2289)      -         
   1.4194     2.7761        11.0       2      a(2289)      -         
   1.6466     2.5753        14.0      10      a(2289)      -         
   1.6466     2.5753        14.0       2      a(2289)      -         
   1.2503     5.4688        35.0       1      a(2289)      -         
   1.2503     5.4688        35.0       2      a(2289)      -         
   1.7991     5.6435        44.5       1      a(2289)      -         
   1.7991     5.6435        44.5       2      a(2289)      -         
   2.6081     4.0042        50.0       1      a(2289)      -         
   2.6081     4.0042        50.0       2      a(2289)      -         
   2.4434     6.3902        79.0       1      a(2289)      -         
   2.4434     6.3902        79.0       2      a(2289)      -         
   2.5819     6.5452        80.5       1      a(2289)      -         
   2.5819     6.5452        80.5       2      a(2289)      -         
   2.7803     7.3967        99.0       1      a(2289)      -         
   2.7803     7.3967        99.0       2      a(2289)      -         
   2.5888     7.0337       100.0       1      a(2289)      -         
   2.5888     7.0337       100.0       2      a(2289)      -         
   2.7015     7.4623       108.0       1      a(2289)      -         
   2.7015     7.4623       108.0       2      a(2289)      -         
   2.6969     7.5158       109.0       1      a(2289)      -         
   2.6969     7.5158       109.0       2      a(2289)      -         
   2.6742     7.5473       111.0       1      a(2289)      -         
   2.6742     7.5473       111.0       2      a(2289)      -         
   0.3625     4.6864       -19.0       2      a(2289)      -         
   0.3625     4.6864       -19.0       3      a(2289)      -         
   0.5808     4.9682        -1.0       2      a(2289)      -         
   0.5808     4.9682        -1.0       3      a(2289)      -         
   0.8164     5.1333        17.0       2      a(2289)      -         
   0.8164     5.1333        17.0       3      a(2289)      -         
   0.8091     5.0199        19.0       2      a(2289)      -         
   0.8091     5.0199        19.0       3      a(2289)      -         
   0.8224     5.2274        19.5       2      a(2289)      -         
   0.8224     5.2274        19.5       3      a(2289)      -         
   0.8880     5.2210        21.0       2      a(2289)      -         
   0.8880     5.2210        21.0       3      a(2289)      -         
   0.8819     5.1326        22.0       2      a(2289)      -         
   0.8819     5.1326        22.0       3      a(2289)      -         
   0.8844     5.1691        30.0       2      a(2289)      -         
   0.8844     5.1691        30.0       3      a(2289)      -         
   1.1998     5.3748        33.0       2      a(2289)      -         
   1.1998     5.3748        33.0       3      a(2289)      -         
   1.2446     5.3015        33.5       2      a(2289)      -         
   1.2446     5.3015        33.5       3      a(2289)      -         
   1.3702     5.5853        38.5       2      a(2289)      -         
   1.3702     5.5853        38.5       3      a(2289)      -         
   1.5718     5.6491        44.0       2      a(2289)      -         
   1.5718     5.6491        44.0       3      a(2289)      -         
   1.8908     5.5900        52.0       2      a(2289)      -         
   1.8908     5.5900        52.0       3      a(2289)      -         
   2.2665     5.7757        58.0       2      a(2289)      -         
   2.2665     5.7757        58.0       3      a(2289)      -         
   2.4352     5.8404        62.5       2      a(2289)      -         
   2.4352     5.8404        62.5       3      a(2289)      -         
   2.5473     6.3706        79.0       2      a(2289)      -         
   2.5473     6.3706        79.0       3      a(2289)      -         
   2.6215     6.8359        96.0       2      a(2289)      -         
   2.6215     6.8359        96.0       3      a(2289)      -         
   2.2096     2.2096        20.0       3      a(2289)      -         
   2.2455     2.1828        21.0       3      a(2289)      -         
   2.3982     2.4231        28.0       3      a(2289)      -         
   2.5890     2.5822        35.0       3      a(2289)      -         
   2.8504     2.8504        42.0       3      a(2289)      -         
   2.9029     7.2751        98.0       3      a(2289)      -         
   0.5273     4.2781       -10.5      10         b         -         
   0.5273     4.2781       -10.5       3         b         -         
   0.4380     4.9458       -10.5       2         b         -         
   0.4380     4.9458       -10.5       3         b         -         
   0.5473     4.2464       -10.0      10         b         -         
   0.5473     4.2464       -10.0       3         b         -         
   0.4457     4.9514       -10.0       2         b         -         
   0.4457     4.9514       -10.0       3         b         -         
   0.8465     3.5248         0.0      10         b         -         
   0.8465     3.5248         0.0       3         b         -         
   0.5495     5.0513         0.0       2         b         -         
   0.5495     5.0513         0.0       3         b         -         
   1.3600     2.8753        10.0      10         b         -         
   1.3600     2.8753        10.0       3         b         -         
   0.6939     5.1623        10.0       2         b         -         
   0.6939     5.1623        10.0       3         b         -         
   1.6098     2.5201        15.0      10         b         -         
   1.6098     2.5201        15.0       3         b         -         
   0.7632     5.2678        15.0       2         b         -         
   0.7632     5.2678        15.0       3         b         -         
   2.8753     1.6764        25.0      10         b        1.0        
   2.8753     1.6764        25.0       3         b        0.00125    
   1.0269     5.3732        25.0       2         b        0.375      
   1.0269     5.3732        25.0       3         b        0.00125    
   1.6414     2.9975        25.65     10         b         -         
   1.6414     2.9975        25.65      3         b         -         
   5.3855     1.0412        25.65      2         b         -         
   5.3855     1.0412        25.65      3         b         -         
   2.9364     2.1759        35.0       1         b         -         
   2.9364     2.1759        35.0       3         b         -         
   1.2906     5.5786        35.0       2         b         -         
   1.2906     5.5786        35.0       3         b         -         
   2.8706     2.5101        38.7       1         b         -         
   2.8706     2.5101        38.7       3         b         -         
   1.3566     5.6574        38.7       2         b         -         
   1.3566     5.6574        38.7       3         b         -         
   0.3719     4.8071       -19.5       0         c         -         
   0.3719     4.8071       -19.5      10         c         -         
   0.3719     4.8071       -19.5       2         c         -         
   0.3719     4.8154       -16.32      2         c         -         
   0.3719     4.8154       -16.32     10         c         -         
   0.3747     4.8182       -16.0       2         c         -         
   0.3747     4.8182       -16.0      10         c         -         
   0.3747     4.8182       -16.0       3         c         -         
   0.4291     4.4984       -10.0      10         c         -         
   0.4291     4.4984       -10.0       3         c         -         
   0.3841     4.8998       -10.0       2         c         -         
   0.3841     4.8998       -10.0       3         c         -         
   0.4585     4.4351       -13.0      10         c         -         
   0.4585     4.4351       -13.0       3         c         -         
   0.3997     4.9125       -13.0       2         c         -         
   0.3997     4.9125       -13.0       3         c         -         
   0.5179     4.3091       -11.02     10         c         -         
   0.5179     4.3091       -11.02      3         c         -         
   0.4302     4.9386       -11.02      2         c         -         
   0.4302     4.9386       -11.02      3         c         -         
   1.0228     3.3092         3.8      10         d         -         
   1.0228     3.3092         3.8       3         d         -         
   3.1103     1.7866        28.5       1         d         -         
   3.1103     1.7866        28.5       3         d         -         
   3.1437     2.2375        38.0       1         d         -         
   3.1437     2.2375        38.0       3         d         -         
   2.8223     3.0886        45.0       1         d         -         
   2.8223     3.0886        45.0       3         d         -         
   2.5198     4.9661        55.4       1         d         -         
   2.5198     4.9661        55.4       3         d         -         
   1.6180     5.6731        44.5       2         d         -         
   1.6180     5.6731        44.5       3         d         -         
   2.1902     5.8575        55.4       2         d         -         
   2.1902     5.8575        55.4       3         d         -         
   2.4162     6.0473        63.4       2         d         -         
   2.4162     6.0473        63.4       3         d         -         
   2.4133     6.0713        63.4       2         d         -         
   2.4133     6.0713        63.4       3         d         -         
   2.4343     6.0382        63.4       2         d         -         
   2.4343     6.0382        63.4       3         d         -         
   2.3940     2.4238        28.6       3         d         -         
   2.5939     2.4752        37.6       3         d         -         
   1.96       0.            25.0      10         e        1.0        
   2.29       0.601         25.0      10         e        1.0        
   2.93       1.72          25.0      10         e        1.0        
   2.93       1.72          25.0       3         e        0.00125    
   2.46       2.17          25.0       3         e        0.00125    
   1.09       5.01          25.0       3         e        0.00125    
   1.02       5.43          25.0       3         e        0.00125    
   1.02       5.43          25.0       2         e        0.375      
   0.         5.82          25.0       2         e        0.375

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: 1 - Na2SO4(s), 10 - Na2SO4.10H2O(s), 2 - (NH4)2SO4(s), 3 - (NH4)2SO4.Na2SO4.4H2O(s), 0 - ice.
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, E. Bovalini and M. Medici (1924) Gazz. Chim. Ital. 54, 934-945; c - U. Sborgi and E. Bovalini (1924) Gazz. Chim. Ital. 54, 919-933; d - S. M. Levi (1924) Z. Physik. Chem. 108, 411-430; e - V. K. Filippov, M. V. Charykova and Yu. M. Trofimov (1987) Zh. Prikl. Khim. 60, 257-262.

(2) Isopiestic Measurements of Osmotic Coefficients

  mNa2SO4  m(NH4)2SO4     t        osm   ref.    weight
   0.000    1.705       25.0      0.623   f        1.0      
   0.109    1.581       25.0      0.639   f        0.0      
   0.340    1.356       25.0      0.627   f        1.0      
   0.530    1.178       25.0      0.622   f        1.0      
   0.661    1.047       25.0      0.622   f        1.0      
   1.171    0.522       25.0      0.628   f        1.0      
   1.531    0.154       25.0      0.631   f        1.0      
   1.697    0.000       25.0      0.626   f        1.0      
   0.000    2.705       25.0      0.632   f        1.0      
   0.115    2.593       25.0      0.631   f        1.0      
   0.277    2.428       25.0      0.632   f        1.0      
   0.354    2.353       25.0      0.632   f        1.0      
   0.518    2.188       25.0      0.632   f        1.0      
   0.637    2.070       25.0      0.632   f        1.0      
   0.778    1.931       25.0      0.631   f        1.0      
   0.961    1.749       25.0      0.631   f        1.0      
   1.146    1.559       25.0      0.632   f        1.0      
   1.268    1.439       25.0      0.632   f        1.0      
   1.558    1.142       25.0      0.633   f        1.0      
   1.672    1.018       25.0      0.634   f        1.0      
   0.000    3.604       25.0      0.651   f        1.0      
   0.153    3.440       25.0      0.653   f        1.0      
   0.368    3.225       25.0      0.653   f        1.0      
   0.469    3.117       25.0      0.654   f        1.0      
   0.684    2.891       25.0      0.656   f        1.0      
   0.842    2.740       25.0      0.655   f        1.0      
   1.024    2.541       25.0      0.658   f        1.0      
   1.262    2.295       25.0      0.660   f        1.0      
   1.502    2.044       25.0      0.662   f        1.0      
   1.656    1.881       25.0      0.663   f        1.0      
   2.030    1.481       25.0      0.667   f        1.0      
   2.183    1.328       25.0      0.668   f        1.0      
   0.000    4.476       25.0      0.672   f        1.0      
   0.190    4.275       25.0      0.674   f        1.0      
   0.455    3.991       25.0      0.677   f        1.0      
   0.843    3.565       25.0      0.683   f        1.0      
   1.034    3.364       25.0      0.684   f        1.0      
   1.255    3.133       25.0      0.689   f        1.0      
   1.542    2.805       25.0      0.692   f        1.0      
   1.829    2.489       25.0      0.697   f        1.0      
   2.016    2.289       25.0      0.699   f        1.0      
   2.452    1.797       25.0      0.708   f        1.0      
   2.629    1.600       25.0      0.712   f        1.0      
   0.000    5.747       25.0      0.702   f        1.0      
   0.242    5.465       25.0      0.710   f        1.0      
   0.579    5.080       25.0      0.716   f        1.0      
   0.735    4.886       25.0      0.721   f        1.0      
   1.067    4.511       25.0      0.727   f        1.0      
   1.302    4.236       25.0      0.732   f        1.0

Notes and References

Prefix m denotes molality; t - experimental temperature (^oC); osm - molal osmotic coefficient; ref. - source of data; weight - the weight given to the data point in the fit of the model (normalised).
Sources: f - V. K. Filippov, M. V. Charykova and Yu. M. Trofimov (1987) Zh. Prikl. Khim. 60, 257-262.

(3) Osmotic Coefficients from Water Activity Measurements

  mNa2SO4   m(NH4)2SO4      t        osm      ref.    weight
   0.1592     1.4485      25.0      0.639      g        0.0 
   0.3206     1.2766      25.0      0.643      g        0.0 
   0.4779     1.1150      25.0      0.645      g        0.0 
   0.6352     0.9569      25.0      0.645      g        0.0 
   0.8026     0.7994      25.0      0.641      g        0.0 
   0.9524     0.6375      25.0      0.646      g        0.0 
   1.1104     0.5274      25.0      0.627      g        0.0 
   1.3312     0.3349      25.0      0.616      g        0.0 
   1.4958     0.1680      25.0      0.617      g        0.0 
   0.1719     1.5640      25.0      0.626      g        0.0 
   0.3511     1.3985      25.0      0.621      g        0.0 
   0.5284     1.2330      25.0      0.617      g        0.0 
   0.6988     1.0527      25.0      0.620      g        0.0 
   0.8743     0.8709      25.0      0.622      g        0.0 
   1.0474     0.7011      25.0      0.621      g        0.0 
   1.1823     0.5615      25.0      0.623      g        0.0 
   1.3956     0.3511      25.0      0.622      g        0.0 
   1.5663     0.1760      25.0      0.623      g        0.0 
   0.2296     2.0891      25.0      0.639      g        0.0 
   0.4650     1.8520      25.0      0.640      g        0.0 
   0.6948     1.6212      25.0      0.640      g        0.0 
   0.9149     1.3780      25.0      0.647      g        0.0 
   1.1473     1.1428      25.0      0.647      g        0.0 
   1.3695     0.9168      25.0      0.648      g        0.0 
   1.5496     0.7359      25.0      0.649      g        0.0 
   1.8280     0.4598      25.0      0.648      g        0.0 
   0.3039     2.7656      25.0      0.682      g        0.0 
   0.6154     2.4507      25.0      0.683      g        0.0 
   0.9072     2.1168      25.0      0.692      g        0.0 
   1.1933     1.7975      25.0      0.700      g        0.0 
   1.5046     1.4986      25.0      0.697      g        0.0 
   1.7945     1.2014      25.0      0.699      g        0.0 
   2.0084     0.9538      25.0      0.707      g        0.0 
   0.5037     4.5842      25.0      0.708      g        0.0 
   1.0091     4.0189      25.0      0.717      g        0.0 
   1.5008     3.5020      25.0      0.720      g        0.0 
   1.9520     2.9402      25.0      0.737      g        0.0 
   2.4213     2.4117      25.0      0.746      g        0.0 
   2.8503     1.9081      25.0      0.757      g        0.0

Notes and References

Prefix m denotes molality; t - experimental temperature (^oC); osm - molal osmotic coefficient; ref. - source of data; weight - the weight given to the data point in the fit of the model (normalised).
These data were not included in the fit of the activity coefficient model parameters.
Sources: g - G. S. Kotlyar-Shapirov and A. N. Kirgintsev (1973) Dep. Publ. VINITI 5609-73 (Chem. Abstr. 85:83684).

Model III: Data for Aqueous NH4+ - Na+ - SO42−

The System

Weights

The Data

(1) Solubilities of Solid Phases

(2) Isopiestic Measurements of Osmotic Coefficients

(3) Osmotic Coefficients from Water Activity Measurements

Model III: Data for Aqueous NH₄⁺ - Na⁺ - SO₄²⁻