( 175 ) 



•'•(i — (() neutral mol.; 2,m Ions. 



We have therefore : 



-^^= V,(l-.'r)(l +/?) + . '•(l+«), 

 or with V, (l-j-,?) = y , 1 -f « = /, where therefore / has Iho usual 

 lueaiiiiiu', and y is (he reverse of the so-called associatioM-coenicient: 



Our equation (1) beeomcs therefore: 

 ^' 1 



1 + 



y 1 — .? 



1-^ 



or y being = \f, (1 + /i) : 



/3^ 



1 + 



y 1 — .?;_ 



V. A', 



/ i '1' 



=: V A' 1 J 



(2) 



From this follows, pntting 



y 1 — ,/; 



= ff: 



/? = 



V.ir(i-Lcf) 



Now evidently 



1 + V, A^ 



1 + ff 



1 + 



V' K 



l-fV,A' 



ff 



1 + '/. A' 

 i. e. the value of ^, if ,v or rf = 0, so that we have got tiie pure 



i^.-' 



solvent, for w hich the C([uation = V4 A' holds. Tiierefore we 



obtain : 



/? = i^„ 



l-i^o'^ 





if, ff l>eing very small and appi'oachiug to 0, \\q contout oui-selves 

 with a tirst approximation. 



Substituting for d its value, and taking into account thai y= '/.^ (W 1^), 

 ^vc obtain : 



i^ = il, 1 + 



2 V,(l+/?) 



T^-.)' 



or with 1 +(?=!+ /?„ : 



|J=:i?„ 1 +(1 _/?.,)/ 



(3) 



