Maleic Acid Data

The tables of data for the pure aqueous acid are given below.

(1a) Water Activities from Electrodynamic Balance Measurements

    aW        mfs          m        np    t   uncert.  ref.   weight
  0.9545    0.30964      3.864      1e   22.7  0.009    a      0.0    
  0.9318    0.33585      4.357      1e   22.7  0.009    a      1.0    
  0.9286    0.37007      5.062      1e   22.7  0.009    a      1.0    
  0.9214    0.38294      5.347      1e   22.7  0.009    a      1.0    
  0.9143    0.47711      7.861      1e   22.7  0.009    a      0.0    
  0.8505    0.48725      8.187      1e   22.7  0.009    a      1.0    
  0.8333    0.50033      8.626      1e   22.7  0.009    a      1.0    
  0.8193    0.51828      9.269      1e   22.7  0.009    a      1.0    
  0.8068    0.54179     10.187      1e   22.7  0.009    a      1.0    
  0.7980    0.57473     11.643      1e   22.7  0.009    a      1.0    
  0.7811    0.59493     12.654      1e   22.7  0.009    a      1.0    
  0.7738    0.61319     13.658      1e   22.7  0.009    a      1.0    
  0.7612    0.63093     14.728      1e   22.7  0.009    a      1.0    
  0.7398    0.65603     16.432      1e   22.7  0.009    a      1.0    
  0.7145    0.68970     19.149      1e   22.7  0.009    a      1.0    
  0.6875    0.71613     21.734      1e   22.7  0.009    a      1.0    
  0.6692    0.74575     25.271      1e   22.7  0.009    a      1.0    
  0.6402    0.77333     29.394      1e   22.7  0.009    a      1.0    
  0.6183    0.78745     31.918      1e   22.7  0.009    a      1.0    
  0.6036    0.79200     32.806      1e   22.7  0.009    a      1.0    
  0.5933    0.8         34.462      1e   22.7  0.009    a      1.0    
  0.2570    0.99183       -         1g   22.7  0.009    a      0.0    
  0.3585    0.99544       -         1g   22.7  0.009    a      0.0    
  0.5113    0.97640       -         1g   22.7  0.009    a      0.0    
  0.6290    0.97877       -         1g   22.7  0.009    a      0.0    
  0.6716    0.98828       -         1g   22.7  0.009    a      0.0    
  0.7071    0.98786       -         1g   22.7  0.009    a      0.0    
  0.7365    0.96509       -         1g   22.7  0.009    a      0.0    
  0.8905    0.42822      6.452      1g   22.7  0.009    a      1.0    
  0.3098    0.95451       -         2e   22.7  0.009    a      0.0    
  0.3278    0.93670       -         2e   22.7  0.009    a      0.0    
  0.3606    0.92198       -         2e   22.7  0.009    a      0.0    
  0.4241    0.91092       -         2e   22.7  0.009    a      0.0    
  0.5136    0.87570       -         2e   22.7  0.009    a      0.0    
  0.5341    0.79440     33.288      2e   22.7  0.009    a      1.0    
  0.5530    0.78794     32.012      2e   22.7  0.009    a      1.0    
  0.5795    0.78023     30.587      2e   22.7  0.009    a      1.0    
  0.5995    0.76226     27.623      2e   22.7  0.009    a      1.0    
  0.6209    0.74196     24.772      2e   22.7  0.009    a      1.0    
  0.6394    0.72971     23.259      2e   22.7  0.009    a      1.0    
  0.6700    0.70639     20.728      2e   22.7  0.009    a      1.0    
  0.7108    0.67814     18.153      2e   22.7  0.009    a      1.0    
  0.7419    0.65269     16.191      2e   22.7  0.009    a      1.0    
  0.7733    0.62175     14.162      2e   22.7  0.009    a      1.0    
  0.8       0.59523     12.669      2e   22.7  0.009    a      1.0    
  0.2943    0.98731       -         2g   22.7  0.009    a      0.0    
  0.4473    0.99783       -         2g   22.7  0.009    a      0.0    
  0.5390    0.99392       -         2g   22.7  0.009    a      0.0    
  0.6207    0.97615       -         2g   22.7  0.009    a      0.0    
  0.6555    0.95116       -         2g   22.7  0.009    a      0.0    
  0.6697    0.93959       -         2g   22.7  0.009    a      0.0    
  0.6837    0.93588       -         2g   22.7  0.009    a      0.0    
  0.7065    0.93268       -         2g   22.7  0.009    a      0.0    
  0.7212    0.93013       -         2g   22.7  0.009    a      0.0    
  0.7347    0.92988       -         2g   22.7  0.009    a      0.0    
  0.9016    0.39602      5.649      2g   22.7  0.009    a      1.0    
  0.6400    0.99010       -         3g   22.7  0.009    a      0.0    
  0.6788    0.97678       -         3g   22.7  0.009    a      0.0    
  0.7029    0.97367       -         3g   22.7  0.009    a      0.0    
  0.7119    0.95094       -         3g   22.7  0.009    a      0.0    
  0.7284    0.92504       -         3g   22.7  0.009    a      0.0    
  0.7588    0.91558       -         3g   22.7  0.009    a      0.0    
  0.7816    0.90099       -         3g   22.7  0.009    a      0.0    
  0.7936    0.89242       -         3g   22.7  0.009    a      0.0    
  0.8037    0.86594       -         3g   22.7  0.009    a      0.0    
  0.8107    0.85205       -         3g   22.7  0.009    a      0.0    
  0.8220    0.82101       -         3g   22.7  0.009    a      0.0    
  0.8313    0.77876       -         3g   22.7  0.009    a      0.0    
  0.8422    0.73415       -         3g   22.7  0.009    a      0.0    
  0.8455    0.61627       -         3g   22.7  0.009    a      0.0    
  0.8523    0.52521      9.531      3g   22.7  0.009    a      1.0    
  0.8568    0.49829      8.557      3g   22.7  0.009    a      1.0    
  0.8593    0.49463      8.432      3g   22.7  0.009    a      1.0    
  0.8273    0.54857     10.470      es   22.7  0.009    a      1.0    
  0.4906    0.96214       -         es   22.7  0.009    a      0.0    
  0.7984    0.60394     13.138      es   22.7  0.009    a      1.0    
  0.7924    0.88414       -         gs   22.7  0.009    a      0.0    
  0.8338    0.80811       -         gs   22.7  0.009    a      0.0    
  0.9194    0.30892       -         gs   22.7  0.009    a      0.0

Notes and References

Symbols: aW - water activity; mfs - mass fraction of solute in the particle, as given by Choi and Chan (2002) and at http://ihome.ust.hk/~keckchan/hygroscopic.html; m - solute molality in the particle (only for those particles that appear to be fully aqueous and contain no solid, and which were also given a non-zero weight); np - particle number (suffix e indicates an evaporation experiment in an atmosphere of decreasing relative humidity, and g particle growth in an atmosphere of increasing relative humidity), the es and gs measurements are for stepwise evaporation and growth (see Figure 7 of Choi and Chan, 2002); t - experimental temperature (^oC); uncert. - probable uncertainty in the water activity; ref. - source of data; weight - the weight assigned in the fit of the model to determine parameter values.
Source: a - M. Y. Choi and C. K. Chan (2002) J. Phys. Chem. A 106, 4566-4572.
The uncertainty associated with mfs (and so also the molality m) has three sources: the determination of the dc balancing voltage, solute evaporation, and the standardisation of the particle composition to a single reference state (either dilute solution or solid particle). Based on the scatter in the listed mfs, an overall uncertainty of at least ±0.01 in mfs seems likely. The corresponding values for molality can be obtained using the conversion equation m = (mfs/(1 - mfs)) × (1000/MW) where MW is the molar mass of the acid (116.07 g).

(1b) Osmotic Coefficients from Bulk Solution Measurements

   nS/nW       aW        m         osm        t      uncert.    ref.     weight   
     -         -       0.5000     1.1084     25.0    0.033(a)    a         1.0 
     -         -       1.0000     1.0282     25.0    0.017(a)    a         1.0 
     -         -       1.5000     1.0202     25.0    0.011(a)    a         1.0 
     -         -       2.0000     0.9822     25.0    0.008(a)    a         1.0 
     -         -       2.5000     0.9607     25.0    0.007(a)    a         1.0 
     -         -       3.0000     0.9558     25.0    0.006(a)    a         1.0 
     -         -       0.4727     1.1143     25.0    0.01(b)     b         1.0 
     -         -       0.5238     1.1081     25.0    0.01(b)     b         1.0 
     -         -       0.8900     1.0487     25.0    0.01(b)     b         1.0 
     -         -       0.9927     1.0401     25.0    0.01(b)     b         1.0 
     -         -       1.2750     1.0148     25.0    0.01(b)     b         1.0 
     -         -       1.2980     1.0138     25.0    0.01(b)     b         1.0 
     -         -       1.5420     1.0002     25.0    0.01(b)     b         1.0 
     -         -       1.8110     0.9893     25.0    0.01(b)     b         1.0 
     -         -       2.0700     0.9793     25.0    0.01(b)     b         1.0 
     -         -       2.4530     0.9698     25.0    0.01(b)     b         1.0 
     -         -       2.8040     0.9622     25.0    0.01(b)     b         1.0 
     -         -       3.2620     0.9612     25.0    0.01(b)     b         1.0 
     -         -       6.769      0.9464     25.0    0.028(c)    c         1.0 
     -         -       0.9874     1.0211     22.0    0.17(c)     d         0.0 
     -         -       1.4746     0.9916     22.0    0.12(c)     d         0.0 
     -         -       2.0003     0.9319     22.0    0.086(c)    d         0.0 
     -         -       2.9849     0.8758     22.0    0.059(c)    d         0.0 
     -         -       3.9631     0.9264     22.0    0.045(c)    d         0.0 
     -         -       4.9989     0.9259     22.0    0.036(c)    d         1.0 
  0.10918    0.8893      -          -        25.0    0.009(d)    e          -  
  0.10918    0.8906      -          -        25.0    0.009(d)    e          -  
  0.10917    0.8871      -          -        25.0    0.009(d)    e          -  
  0.01648    0.9739      -          -        25.0    0.009(d)    e          -  
  0.03775    0.9601      -          -        25.0    0.009(d)    e          -  
  0.06301    0.9335      -          -        25.0    0.009(d)    e          -  
  0.01093    0.9790      -          -        25.0    0.009(d)    e          -  
  0.07758    0.9239      -          -        25.0    0.009(d)    e          -  
  0.02658    0.9639      -          -        25.0    0.009(d)    e          -

Notes and References

Symbols: nS/nW - moles of solute per mole of water in the aqueous solution; aW - water activity; m - molality; osm - molal osmotic coefficient; t - experimental temperature (^oC); uncert. - probable uncertainty in the osmotic coefficient or water activity (see note further below); ref. - source of data; weight - the weight assigned in the fit of the model to determine parameter values.
Sources: a - M. Davies and D. K. Thomas (1956) J. Phys. Chem. 60, 41-44; b - R. A. Robinson, P. K. Smith and E. R. B. Smith (1942) Trans. Faraday Soc. 38, 63-70; c - C. Marcolli, B. P. Luo and Th. Peter (2004) J. Phys. Chem. A 108, 2216-2224; d - M. Y. Choi and C. K. Chan (2002) J. Phys. Chem. A 106, 4566-4572; e - E. Wise, J. D. Surratt, D. B. Curtis, J. E. Shilling and M. A. Tolbert (2003) J. Geophys. 108, doi:10.1029/2003JD003775, 8 pages.
The original data of Wise et al. (2003), which are not tabulated in their paper, were obtained directly from the authors.
Uncertainties: (a) in the listed osmotic coefficient osm, based upon ±0.007 mmHg in the measured pressure difference; (b) assumed to be ±0.01 in the osmotic coefficient osm; (c) in the listed osmotic coefficient osm, based upon ±0.003 in the measured water activity aW; (d) in the measured water activity (average of the 0.5% to 1.35% in RH given by Wise et al., 2003).