710 
we get: 
Srp = 20, BH Tl Fg RLS In CR 
If we now bear in mind that in the state of equilibrium: 
Syu=O0 and that RT Zvw, In C, = RT In KC 
it follows from (7) that: 
RT in Kc = — 2v,E, + T2v,H, -_, 
or 
open le =v, E, Pr =v, cn 8 
[MID == ORT ee A . . e Fy e ( ) 
Before we proceed it should be pointed out that 2», /,, which 
quantity denotes the change of energy at the temperature of obser- 
vation, is practically independent of the temperature, and may, 
therefore, be considered as a constant; because the sum of the 
specific heats of the second member of the equation of reaction 
diminished with the sum of the specifie heats of the first member 
yields a quantity perfectly negligible here as was lately fully de- 
monstrated by Dr. SCHEFFER '). 
The solution of the problem now under discussion, is exceedingly 
simple, when the sum of the entropies Zr, //,,_, has the same 
value in the different solvents, at least so little different that the 
deviations can be entirely neglected by the side of the sums of the 
energies Zr,£, ’). 
This case can of course only be expected when the influence of 
the solvent on the dissolved substance is of exclusively physical 
nature. 
If we, therefore, apply equation (8) to the same equilibrium in 
two different solvents / and //, the just mentioned supposition 
comes to this that in the equations: 
Lud (Sr yy 4 
In ky Ze ORT BS. + Cy . ? ; ‘ . : : (9) 
and 
=v, 
ln Kj= = ae = Cr . 5 e . a 5 (10) 
tbe relation : 
Gi On En LE AE En (11) 
1) This part of these Proceedings p. 656. 
2?) This assumption is of the same nature as that introduced by Dr. SCHEFFER 
in his paper “On the Velocity of Substitutions in the benzene nucleus’. He assumed 
there that the “difference in substitution entropy would be zero for the different 
hydrogen atoms”. ‘hese Proc. Vol. XV. p. 1118. 
