164 A Theory of Solutions. 
2 
al = <a = K by no means 
agrees with the behaviour of strong electrolytes. 
Let us suppose that there is a binary salt, as NaCl, 
dissolved in water; then we get from Guldberg-Waage’s law 
the known equation 2 
De — K e 
dye 
Further, we may assume that water consists of double and 
single molecules, then there will be an equilibrium which is 
characterized by the validity of a corresponding formula 
one knows that Ostwald’s formula 
2 
(Paar = s = K,,, where y,, is the coefficient of dissociation of 
double molecules of water into single ones, v, means the 
volume of water, and K,, is the constant of equilibrium. 
If we dissolve a salt and assume that the ions of the same 
(whether dissociated or not) are able to join with the single 
molecules of the solvent present and to dissociate the double 
molecules, the equilibrium of the double and single molecules 
of water evidently will be changed, and truly the hypothesis * 
is justified that the change of the constant K,, is proportional 
to the concentration of the salt-ions ”, and therefore 
KK = K ie Y 4 
(D) 
If we compare on the other hand different solvents, it is certain 
that solvent will have the largest dissociating power in which 
the number of the single molecules and especially the tendency 
for their formation is greatest. Therefore the change of the 
constant K for the dissociation of the salt is approximately pro- 
portional to the concentration of the single molecules of the 
solvent, that is = and consequently K= K~ ise! 
Water is the most associated liquid. By that we are 
justified in supposing that the number of the existing single 
molecules is very small f (Jones /.c., and others) ; therefore 
the difference in the result is not large, if we put l—yw=1. 
rry 2 = 
‘hen we get en, as Tenge vy) = 
i = w or w VAs 3 
w 
Wis 
and since yw» 1s= K7 the formula results 
Ky,, aan 
Kr ih J Kavy 5 
* Euler, Zeitschr. Physik. Chem, xxviii. p. 619 (1899), and xxix. 
p. 603 (1899). 
+ It is possible that the tendency to their formation is very great. 
