The System

The sources of data used to determine mixture parameters W, Q and U in the activity coefficient equations for this ternary system are listed in Table 13 of Carslaw et al. (1995), and in section 3.6 of Clegg et al. (1998a). Fits of the model are described in section IV.6 of Carslaw et al. (See also Table 5 of Massucci et al. (1999) for additional data for some quaternary mixtures with HNO3.) The following types of data were used:

1. Rates of uptake of HCl(g) by aqueous H2SO4.
2. The effective Henry's law constant of HCl in aqueous H2SO4.
3. The solubility of HCl in aqueous H2SO4, for fixed gas phase pressures of HCl.

References:
K. S. Carslaw, S. L. Clegg and P. Brimblecombe (1995) J. Phys. Chem. 99, 11557-11574.
S. L. Clegg, P. Brimblecombe and A. S. Wexler (1998a) J. Phys. Chem. A 102, 2137-2154.
M. Massucci, S. L. Clegg and P. Brimblecombe (1999) J. Phys. Chem. A 103, 4209-4226.

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.

All weights for this system are listed as '-', because most data were satisfactorily predicted with ternary interaction parameters set to zero, and were therefore not fitted. See Figures 12 and 13 of Carslaw et al. (1995) for comparisons.

The Data

The experimental data for this system 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) Uptake Rates of HCl(g) by Aqueous H2SO4

    T     mH2SO4      Y       ref.   weight    D          cH2SO4                  
  200.00  15.042     7.1       c       -     1.1E-8       9.5157               
  205.00  15.042     5.95      c       -     2.15E-8      9.4952               
  205.00  15.042     6.4       c       -     2.15E-8      9.4952               
  210.00  15.042     4.65      c       -     3.88E-8      9.4744               
  220.00  15.042     3.0       c       -     1.04E-7      9.4321               
  220.00  15.042     3.7       c       -     1.04E-7      9.4321               
  200.00  15.042     8.1       c       -     1.1E-8       9.5157               
  225.00  12.770     11.5      c       -     2.03E-7      8.5390               
  225.00  12.770     11.0      c       -     2.03E-7      8.5390               
  215.00  12.770     15.4      c       -     8.8E-8       8.5785               
  205.00  12.770     28.1      c       -     3.1E-8       8.6168               
  230.00  10.400     35.1      c       -     3.66E-7      7.4631               
  215.00  10.400     77.5      c       -     1.15E-7      7.5158               
  215.00  10.400     75.5      c       -     1.15E-7      7.5158               
  207.00  10.400     146.0     c       -     5.3E-8       7.5428               
  200.00  10.400     156.0     c       -     2.3E-8       7.5658               

Notes and References

• Prefix m denotes molality; and prefix c molarity; T - experimental temperature (K); Y - the measured quantity, H* x SQRT(D), where H* is the molar effective Henry's law constant (mol dm^-3 atm^-1), and D is the diffusivity of HCl (cm² s^-1) in aqueous H2SO4; ref. - source of data; weight - the weight given to the data point in the fit of the model (normalised).
• The values of D were obtained using the cubic cell model described by Luo et al. (Geophys. Res. Lett. 21, 49-52, 1994). Conversion of H* to a molality basis (i.e., mol kg^-1 atm^-1) was carried out using equation (26) of Carslaw et al. (1995), and their equation (A10) for the density of aqueous H2SO4. (Values of H* from the table can be converted to molal units by multiplying by the factor cH2SO4/mH2SO4.)
• Source: c - D. R. Hanson and A. R. Ravishankara (1993) J. Phys. Chem. 97, 12309-12319.

(2) Effective Henry's law Constants of HCl in Aqueous H2SO4

     T    mH2SO4      H*      log10(H*)    ref.   weight         cH2SO4          
  218.00  8.3430     1.7E6                  c       -            6.4336          
  203.20  8.3430     7.2E6                  c       -            6.4756          
  195.00  8.3430     2.5E7                  c       -            6.4978          
  200.00  8.4440     1.3E7                  c       -            6.5412          
  210.00  8.4440     3.6E6                  c       -            6.5132          
  220.00  8.4440     1.2E6                  c       -            6.4840          
  200.00  8.4440     1.3E7                  c       -            6.5412          
  195.00  8.4440     2.4E7                  c       -            6.5548          
  195.00  8.4440     2.2E7                  c       -            6.5548          
  200.00  10.196     3.1E6                  c       -            7.4654          
  200.00  10.196     3.6E6                  c       -            7.4654          
  206.00  10.196     1.7E6                  c       -            7.4460          
  212.50  10.196     8.5E5                  c       -            7.4245          
  205.30  10.660     1.1E6                  c       -            7.6741          
  199.00  10.660     2.4E6                  c       -            7.6950          
  209.80  10.660     6.0E5                  c       -            7.6588          
  219.50  10.660     2.3E5                  c       -            7.6251          
  199.70  10.660     2.8E6                  c       -            7.6927          
  228.83  10.196                5.15        d       -            7.3683          
  228.57  10.196                5.20        d       -            7.3692          
  226.24  10.196                5.30        d       -            7.3774          
  224.72  10.196                5.52        d       -            7.3827          
  221.73  10.196                5.57        d       -            7.3931          
  221.73  10.196                5.75        d       -            7.3931          
  220.75  10.196                5.68        d       -            7.3965          
  220.26  10.196                5.90        d       -            7.3982          
  219.30  10.196                5.97        d       -            7.4015          
  218.34  10.196                6.00        d       -            7.4048          
  218.58  10.196                5.89        d       -            7.4040          
  228.57  12.462                4.45        d       -            8.3965          
  226.76  12.462                4.40        d       -            8.4037          
  225.73  12.462                4.60        d       -            8.4078          
  225.23  12.462                4.50        d       -            8.4098          
  223.21  12.462                4.80        d       -            8.4178          
  223.21  12.462                4.72        d       -            8.4178          
  221.73  12.462                4.70        d       -            8.4236          
  221.48  12.462                4.79        d       -            8.4246          
  220.99  12.462                4.98        d       -            8.4265          
  219.78  12.462                4.95        d       -            8.4312          
  219.30  12.462                5.02        d       -            8.4331          
  216.68  12.462                4.90        d       -            8.4432          
  216.22  12.462                4.85        d       -            8.4450          
  227.27  15.295                4.00        d       -            9.4902          
  225.73  15.295                4.05        d       -            9.4969          
  224.72  15.295                4.30        d       -            9.5013          
  222.22  15.295                4.35        d       -            9.5122          
  220.26  15.295                4.55        d       -            9.5207          
  203.05  15.295                5.10        d       -            9.5935          

Notes and References

• Prefixes m and c denote molality and molarity, respectively; T - experimental temperature (K); H* - the molar effective Henry's law constant (mol dm^-3 atm^-1); ref. - source of data; weight - the weight given to the data point in the fit of model (normalised).
• Conversion of H* to a molality basis (i.e., mol kg^-1 atm^-1) was carried out using equation (26) of Carslaw et al. (1995), and their equation A10 for the density of aqueous H2SO4. (Values of H* from the table can be converted to molal units by multiplying by the factor cH2SO4/mH2SO4.)
• Sources: c - D. R. Hanson and A. R. Ravishankara (1993) J. Phys. Chem. 97, 12309-12319; d - L. R. Williams and D. M. Golden (1993) Geophys. Res. Lett. 20, 2227-2230, (taken from their Figure 3).

(3) Effective Henry's law Constants of HCl in Aqueous H2SO4

     T      mH2SO4       H*     ref.   weight             cH2SO4          
  208.00    5.4900     6.416E7   e       -                4.6776                      
  210.00    5.4900     4.853E7   e       -                4.6739          
  212.00    5.4900     3.689E7   e       -                4.6701          
  215.00    5.4900     2.469E7   e       -                4.6644          
  220.00    5.4900     1.296E7   e       -                4.6548          
  225.00    5.4900     6.998E6   e       -                4.6449          
  230.00    5.4900     3.882E6   e       -                4.6349          
  232.00    5.4900     3.088E6   e       -                4.6308          
  198.00    6.7980     5.098E7   e       -                5.5651          
  200.00    6.7980     3.788E7   e       -                5.5606          
  205.00    6.7980     1.849E7   e       -                5.5492          
  210.00    6.7980     9.342E6   e       -                5.5377          
  215.00    6.7980     4.871E6   e       -                5.5258          
  220.00    6.7980     2.616E6   e       -                5.5137          
  225.00    6.7980     1.445E6   e       -                5.5014          
  230.00    6.7980     8.185E5   e       -                5.4889          
  232.00    6.7980     6.566E5   e       -                5.4838          
  198.00    10.196     1.369E6   e       -                7.4718          
  200.00    10.196     1.035E6   e       -                7.4654          
  205.00    10.196     5.273E5   e       -                7.4493          
  210.00    10.196     2.774E5   e       -                7.4328          
  215.00    10.196     1.504E5   e       -                7.4161          
  220.00    10.196     8.381E4   e       -                7.3991          
  225.00    10.196     4.794E4   e       -                7.3818          
  230.00    10.196     2.810E4   e       -                7.3641          
  232.00    10.196     2.284E4   e       -                7.3570          
  193.00    15.295     4.962E4   e       -                9.6347          
  195.00    15.295     3.821E4   e       -                9.6265          
  200.00    15.295     2.033E4   e       -                9.6061          
  205.00    15.295     1.116E4   e       -                9.5854          
  210.00    15.295     6.302E3   e       -                9.5645          

Notes and References

• Prefixes m and c denote molality and molarity, respectively; T - temperature (K); H* - the molar effective Henry's law constant of HCl in aqueous H2SO4 (mol dm^-3 atm^-1) ref. - source of data; weight - the weight given to the data point in the fit of model (normalised).
• The listed values were calculated using the fitted equations given by the authors in their Table VI. Conversion of H* to a molality basis (i.e., mol kg^-1 atm^-1) was carried out using equation (26) of Carslaw et al. (1995), and their equation A10 for the density of aqueous H2SO4. (Values of H* from the table above can be converted to molal units by multiplying by the factor cH2SO4/mH2SO4.)
• These data were found to agree poorly with model predictions, and with other data. See Figure 13 of Carslaw et al. (1995).
• Sources: e - R. Y. Zhang, P. J. Wooldridge, J. P. D. Abbatt and M. J. Molina (1993) J. Phys. Chem. 97, 8541-8548.

(4) Solubilities of HCl in Aqueous H2SO4

  mH2SO4  mHCl        t   ref.   weight                        
  16.771  3.455     40.0    a       -                      
  23.311  1.335     40.0    a       -                      
  30.902  0.416     40.0    a       -                      
  40.256  0.224     40.0    a       -                      
  37.968  0.210     40.0    a       -                      
  53.973  0.168     40.0    a       -
   1.002  21.025     0.0    a       -                      
   1.180  21.309     0.0    a       -                      
   3.106  19.191     0.0    a       -                      
   3.485  19.366     0.0    a       -                      
   6.877  16.440     0.0    a       -                      
   7.457  16.074     0.0    a       -                      
  13.244  11.468     0.0    a       -                      
  17.816   8.196     0.0    a       -                      
  21.148   5.382     0.0    a       -                      
  22.888   4.625     0.0    a       -                      
  25.319   3.230     0.0    a       -                      
  31.903   1.701     0.0    a       -                      
  50.461   0.426     0.0    a       -                    
   2.798  22.907   -15.8    a       -                      
   2.891  21.285   -15.8    a       -                      
   6.268  20.000   -15.8    a       -                      
  10.111  11.217   -15.8    a       -                      
  10.258  16.407   -15.8    a       -                      
  10.311  16.117   -15.8    a       -                      
  10.520  16.383   -15.8    a       -                      
  10.432  16.192   -15.8    a       -                      
  11.722  14.556   -15.8    a       -                      
  11.727  14.431   -15.8    a       -                      
  12.753  13.140   -15.8    a       -                      
  12.946  13.040   -15.8    a       -                      
  14.457  12.594   -15.8    a       -                      
  14.492  12.961   -15.8    a       -                      
  14.746  12.288   -15.8    a       -                      
  16.165  10.130   -15.8    a       -                      
  17.770  10.462   -15.8    a       -                      
  18.002   9.817   -15.8    a       -                      
  18.198   9.440   -15.8    a       -                      
  18.389   9.088   -15.8    a       -                      
  25.568   4.565   -15.8    a       -                      
  25.606   3.669   -15.8    a       -                      
  26.168   3.685   -15.8    a       -                      
  26.246   3.618   -15.8    a       -                      
   5.091  22.278   -25.0    a       -                      
   5.114  21.187   -25.0    a       -                      
   6.019  20.423   -25.0    a       -                      
   6.079  20.820   -25.0    a       -                      
   9.288  17.921   -25.0    a       -                      
  10.698  18.120   -25.0    a       -                      
  11.425  18.345   -25.0    a       -                      
  12.852  15.830   -25.0    a       -                      
  15.500  14.197   -25.0    a       -                      
  16.281  12.806   -25.0    a       -                      
  18.119  10.991   -25.0    a       -                      
  22.653   8.558   -25.0    a       -                      
  22.664   7.875   -25.0    a       -                      
  0.000   20.458    17.0    b       -            
  0.313   18.786    17.0    b       -            
  0.861   19.193    17.0    b       -            
  1.484   18.315    17.0    b       -            
  2.422   16.819    17.0    b       -            
  4.221   15.383    17.0    b       -            
  6.748   13.307    17.0    b       -            
 11.288   10.256    17.0    b       -            
 17.287    4.969    17.0    b       -            
 21.293    2.827    17.0    b       -            
 29.310    0.658    17.0    b       -            
 35.353    0.136    17.0    b       -            
 83.027    0.166    17.0    b       -            
  0.598   15.982    40.0    b       -            
  1.009   16.090    40.0    b       -            
  1.544   15.111    40.0    b       -            
  3.090   13.594    40.0    b       -            
  3.477   12.852    40.0    b       -            
  5.519    9.549    40.0    b       -            
 10.153    7.118    40.0    b       -            
 17.547    2.579    40.0    b       -            
 20.886    0.991    40.0    b       -            
 28.014    0.176    40.0    b       -            
 39.566    0.105    40.0    b       -            
 44.672    0.048    40.0    b       -            
 51.801    0.049    40.0    b       -            
  0.250   13.610    70.0    b       -            
  0.531   12.975    70.0    b       -            
  0.754   12.899    70.0    b       -            
  5.883   13.549    70.0    b       -            
  3.318   10.733    70.0    b       -            
  3.537   10.584    70.0    b       -            
  7.304    7.150    70.0    b       -            
 10.850    4.236    70.0    b       -            
 17.847    1.193    70.0    b       -            
 21.660    0.466    70.0    b       -            
 42.653    0.072    70.0    b       -            
 49.852    0.057    70.0    b       -            
 51.288    0.053    70.0    b       -            

Notes and References

• Prefix m denotes molality; t - experimental temperature (^oC); ref. - source of data; weight - the weight given to the data point in the fit of model (normalised).
• The equilibrium vapour pressures of HCl are 260 mm Hg for data at -25 ^oC, and 760 mm Hg for data at all other temperatures.
• Source: a - V. Cupr (1928) Rec. Trav. Chim. 47, 55-72; b - A. Coppadoro (1909) Gazz. Chim. Ital. 39, 616-642.