those of Lewis et al. (10) by: 
tt "! mM. 4y¥m ym _ 
eats C = 2. 303RT- z 
arto, 
dB/dT  dC/dT Im,M;/ \(2m,) 
Ga 
B'" is also related to the constant B' used earlier in the 
heat-capacity equation by: 
B" a ele eee (12) 
dB/dT 
2 GB 
Ted 
The calculated values of enthalpy change of mixing using 
these equations are in good agreement with the observed 
values for low salinity solutions. However, the deviations 
aRemneLacively Sienahucant at higher concentrations. It is 
believed that these deviations can be reduced through use of 
a two-structure model which takes the concentrated solution 
behavior into account. Development and evaluation of such 
Nodelseissin propressiethe detallsiwill berpresented in a 
Racer publication’. 
Results 
Relative Enthalpies: The relative enthalpies of sea 
salt solutions at 25°C and at 50°C have been reported 
camiver 1(2)' and are’ reproduced in Tables 8 'and 9. 
The data at 73°C were correlated through the applica- 
tion of extended Debye-Huckel theory, as was done earlier 
for, lower ‘temperatures. Selected values of the observed 
and correlated heats of mixing are given in Table 10. The 
agreement appears to be good at lower salinities, though 
the deviations tend to increase with increasing salinity. 
It is hoped that a two structure model would provide a 
Detter fit of the? data: 
The values of C'’ and n used in these calculations were 
iOS oO eond ao Gespectiviely. “ihe best value Of BB sielected 
by the computer was 3.3296. 
habe mol saves the srelative enthalpies Of sea salt 
solutions at 73°, based on these computations. The corre- 
sponding partial and apparent enthalpies are given in Table 12. 
5 
