Malonic 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
  0.9031      0.36567      5.540    1e  25.0  0.01     a      1.0           
  0.8500      0.45648      8.07     1e  25.0  0.01     a      1.0           
  0.8095      0.51061     10.03     1e  25.0  0.01     a      1.0           
  0.7111      0.60351     14.63     1e  25.0  0.01     a      1.0           
  0.6434      0.66707     19.26     1e  25.0  0.01     a      1.0           
  0.5246      0.74560     28.16     1e  25.0  0.01     a      1.0           
  0.3564      0.88027     70.67     1e  25.0  0.01     a      1.0           
  0.1075      1.0           -       1e  25.0  0.01     a      0.0           
  0.8500      0.46800      8.45     2e  25.0  0.01     a      1.0           
  0.6039      0.71630     24.26     2e  25.0  0.01     a      1.0           
  0.8500      0.46800      8.45     2e  25.0  0.01     a      1.0           
  0.3981      0.87663     68.27     2e  25.0  0.01     a      1.0           
  0.8500      0.46800      8.45     2e  25.0  0.01     a      1.0           
  0.2088      0.94069    152.4      2e  25.0  0.01     a      1.0           
  0.8552      0.45942      8.17     2e  25.0  0.01     a      1.0           
  0.8525      0.46800      8.45     3e  25.0  0.01     a      1.0           
  0.6518      0.72316     25.11     3e  25.0  0.01     a      1.0           
  0.5513      0.76637     31.53     3e  25.0  0.01     a      1.0           
  0.4525      0.83231     47.69     3e  25.0  0.01     a      1.0           
  0.2508      0.95615    209.29     3e  25.0  0.01     a      1.0           
  0.1508      1.0           -       3g  25.0  0.01     a      0.0           
  0.3275      0.93360    135.1      3g  25.0  0.01     a      1.0           
  0.4960      0.86158     59.83     3g  25.0  0.01     a      1.0           
  0.7524      0.62608     16.09     3g  25.0  0.01     a      1.0           
  0.9106      0.36542      5.53     3g  25.0  0.01     a      1.0

Notes and References

Symbols: aW - water activity; mfs - mass fraction of solute in the particle, as given by Peng et al. (2001) and at http://ihome.ust.hk/~keckchan/hygroscopic.html; m - solute molality of the particles (only those particles that appear to be fully aqueous and which were 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); 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 - C. Peng, M. N. Chan and C. K. Chan (2001) Environ. Sci. Technol. 35, 4495-4501.
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 (104.06 g).
Further edb measurements by M. Y. Choi and C. K. Chan (J. Phys. Chem. A. 106, 4566-4572, 2002), see their Figure 3, are consistent with the above data.

(1b) Osmotic Coefficients from Bulk Solution Measurements

   nS/nW     aW         m          osm       t     uncert.   ref.   weight 
     -        -       0.4994      1.342     25.0   0.34(a)    a      0.  
     -        -       1.0099      0.998     25.0   0.17(a)    a      1.0 
     -        -       1.4985      0.938     25.0   0.11(a)    a      1.0 
     -        -       1.9906      0.965     25.0   0.087(a)   a      1.0 
     -        -       1.9767      0.884     25.0   0.087(a)   a      1.0 
     -        -       2.9817      0.994     25.0   0.059(a)   a      1.0 
     -        -       4.0018      0.977     25.0   0.045(a)   a      1.0 
     -        -       5.0059      0.997     25.0   0.036(a)   a      1.0 
     -        -       5.9804      1.030     25.0   0.031(a)   a      1.0 
     -        -       6.9531      1.039     25.0   0.027(a)   a      1.0 
     -        -       7.9842      1.065     25.0   0.024(a)   a      1.0 
     -        -       0.4610      1.0590    25.0   0.036(b)   b      1.0 
     -        -       0.9920      1.0270    25.0   0.017(b)   b      1.0 
     -        -       1.7290      0.9770    25.0   0.010(b)   b      1.0 
     -        -       2.5450      0.9381    25.0   0.007(b)   b      1.0 
     -        -       2.8200      0.9350    25.0   0.006(b)   b      1.0 
     -        -       3.4360      0.9366    25.0   0.005(b)   b      1.0 
     -        -       3.9450      0.9374    25.0   0.004(b)   b      1.0 
     -        -       4.3870      0.9396    25.0   0.004(b)   b      1.0 
     -        -       4.8380      0.9518    25.0   0.004(b)   b      1.0 
     -        -       0.5037      0.3311    25.0   0.33(a)    c      0.0 
     -        -       1.0642      0.7354    25.0   0.16(a)    c      0.0 
     -        -       2.3920      0.8027    25.0   0.072(a)   c      0.0 
     -        -       4.0970      0.9106    25.0   0.044(a)   c      1.0 
     -        -       6.3693      0.9960    25.0   0.029(a)   c      1.0 
     -        -       9.5447      1.1047    25.0   0.021(a)   c      1.0 
     -        -      15.22        1.179     25.0   0.015(a)   d      1.0 
  0.28487   0.7084      -           -       25.0   0.009(c)   e       -  
  0.28487   0.7084      -           -       25.0   0.009(c)   e       -  
  0.28487   0.7272      -           -       25.0   0.009(c)   e       -  
  0.28487   0.7208      -           -       25.0   0.009(c)   e       -  
  0.28487   0.7093      -           -       25.0   0.009(c)   e       -  
  0.17641   0.8185      -           -       25.0   0.009(c)   e       -  
  0.11968   0.8813      -           -       25.0   0.009(c)   e       -  
  0.09716   0.9386      -           -       25.0   0.009(c)   e       -  
  0.02204   0.9841      -           -       25.0   0.009(c)   e       -  
  0.01148   0.9816      -           -       25.0   0.009(c)   e       -  
  0.03699   0.9608      -           -       25.0   0.009(c)   e       -  
  0.02180   0.9824      -           -       25.0   0.009(c)   e       -  
  0.02763   0.9639      -           -       25.0   0.009(c)   e       -  
  0.01572   0.9734      -           -       25.0   0.009(c)   e       -  
  0.01352   0.9800      -           -       25.0   0.009(c)   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 data (see additional note further below); ref. - source of data; weight - the weight assigned in the fit of the model to determine parameter values.
Sources: a - C. Peng, M. N. Chan and C. K. Chan (2001) Environ. Sci. Technol. 35, 4495-4501; b - M. Davies and D. K. Thomas (1956) J. Phys. Chem. 60, 41-44; c - M. C. Maffia and A. J. A. Meirelles (2001) J. Chem. Eng. Data 46, 582-587; d - C. Marcolli, B. P. Luo and Th. Peter (2004) J. Phys. Chem. A 108, 2216-2224; 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 ±0.003 in the measured water activity aW; (b) in the listed osmotic coefficient osm, based upon ±0.007 mmHg in the measured pressure difference; (c) in the measured water activity (average of the 0.5% to 1.35% in RH given by Wise et al., 2003).