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

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 10 of Clegg et al. (1998b). Fits of the model are described in section 3.12 of that paper. The following type of data was used:
  1. Saturation with respect to the solids (NH4)2SO4(s) and NH4Cl(s) in the ternary solutions.
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

  mNH4Cl   m(NH4)2SO4      t     solid     ref.     weight        
  5.0081     3.5185      21.5      1     a(2267)      -            
  5.0081     3.5185      21.5      2     a(2267)      -            
  7.8226     0.0         30.0      1     a(2268)      -      
  8.0120     0.5690      30.0      1     a(2268)      -      
  7.4721     1.1770      30.0      1     a(2268)      -      
  7.0181     1.8369      30.0      1     a(2268)      -      
  6.3149     2.5311      30.0      1     a(2268)      -      
  6.0337     3.3369      30.0      1     a(2268)      -      
  6.0337     3.3369      30.0      2     a(2268)      -      
  4.3446     3.9972      30.0      2     a(2268)      -      
  2.8125     4.6882      30.0      2     a(2268)      -      
  0.9151     5.2924      30.0      2     a(2268)      -      
  0.0        5.4803      30.0      2     a(2268)      -      
  7.8226     0.0         30.0      1     a(2269)      -      
  7.1148     1.5227      30.0      1     a(2269)      -      
  6.7931     2.0138      30.0      1     a(2269)      -      
  6.3568     2.7448      30.0      1     a(2269)      -           
  6.1776     3.0451      30.0      1     a(2269)      -           
  5.9580     3.4720      30.0      1     a(2269)      -           
  5.9580     3.4720      30.0      2     a(2269)      -           
  5.8019     3.4284      30.0      2     a(2269)      -           
  4.8136     3.8120      30.0      2     a(2269)      -           
  2.2503     4.8006      30.0      2     a(2269)      -           
  0.0        5.9463      30.0      2     a(2269)      -           
  4.6330     1.5246       0.0      1     a(2270)      -           
  3.5033     3.5644       0.0      1     a(2270)      -           
  3.5033     3.5644       0.0      2     a(2270)      -           
  6.5460     1.3539      25.0      1     a(2270)    0.5           
  5.3414     3.4544      25.0      1     a(2270)    0.5           
  5.3414     3.4544      25.0      2     a(2270)    0.5           
  6.4996     3.3636      40.0      1     a(2270)      -           
  6.4996     3.3636      40.0      2     a(2270)      -           
  9.3632     1.4905      60.0      1     a(2270)      -           
  8.7193     3.8588      60.0      1     a(2270)      -           
  8.7193     3.8588      60.0      2     a(2270)      -           
 10.3691     3.5542      80.0      1     a(2270)      -           
 10.3691     3.5542      80.0      2     a(2270)      -           
  6.6553     0.0         15.5      1     a(2271)      -           
  5.9636     1.7482      15.5      1     a(2271)      -           
  5.3841     2.5202      15.5      1     a(2271)      -           
  5.0289     4.0943      15.5      1     a(2271)      -           
  4.9915     4.2533      15.5      1     a(2271)      -           
  4.9915     4.2533      15.5      2     a(2271)      -           
  4.1502     4.3138      15.5      2     a(2271)      -           
  3.2155     4.5106      15.5      2     a(2271)      -           
  0.0        5.7200      15.5      2     a(2271)      -           
  7.3244     0.0000      25.0      1     a(2272)    0.0           
  6.8881     0.8421      25.0      1     a(2272)    0.5           
  6.2562     1.8514      25.0      1     a(2272)    0.5           
  5.2876     3.4236      25.0      1     a(2272)    0.5           
  5.2876     3.4236      25.0      2     a(2272)    0.5           
  3.7272     4.1010      25.0      2     a(2272)    0.5           
  1.9873     4.8815      25.0      2     a(2272)    0.5           
  0.0000     5.7560      25.0      2     a(2272)    0.0           
  6.9919     0.0000      20.0      1     a(2273)      -           
  6.6503     0.5822      20.0      1     a(2273)      -           
  6.3179     1.0235      20.0      1     a(2273)      -           
  6.0427     1.5136      20.0      1     a(2273)      -           
  5.8051     2.9659      20.0      1     a(2273)      -           
  5.0428     3.6725      20.0      1     a(2273)      -           
  5.0428     3.6725      20.0      2     a(2273)      -           
  3.9275     4.0914      20.0      2     a(2274)      -           
  1.8512     4.8996      20.0      2     a(2274)      -           
  0.0000     5.5961      20.0      2     a(2274)      -           
  7.7770     0.0000      30.0      1      b           -      
  6.8423     0.7341      30.0      1      b           -      
  6.2253     1.4909      30.0      1      b           -      
  6.1132     2.4596      30.0      1      b           -      
  5.9262     3.0424      30.0      1      b           -      
  5.8888     3.3829      30.0      1      b           -      
  5.8888     3.3829      30.0      2      b           -      
  5.4402     3.4813      30.0      2      b           -      
  3.6081     4.2684      30.0      2      b           -      
  0.0        5.6420      30.0      2      b           -      
  2.1887     3.8517     -22.5      0      c           -      
  2.1887     3.8517     -22.5      1      c           -      
  2.1887     3.8517     -22.5      2      c           -      
  6.2892     3.8750      10.0      1      d           -      
  6.2892     3.8750      10.0      2      d           -      
  5.313      3.436       25.0      2      e         0.5      
  5.313      3.436       25.0      2      e         1.0      
Notes and References