KAHLENBERG — THEORY OP ELECTROLYTIC DISSOCIATION. 315 



found that the degree of dissociation of KC1, while nearly the 

 same by cryoscopic and conductivity methods at a concentra- 

 tion slightly above 0.1 normal, increases more rapidly with the 

 dilution by the latter than by the former method. 



In the case of MgS0 4 (Table 4) the solutions examined 

 varied in concentration from about 0.1 to 1.5 normal. The de- 

 gree of dissociation for the most dilute solution being 40 per 

 cent, and for the most concentrated only 5 per cent. Accord- 

 ing to the conductivity determinations (Table 1) the corre- 

 sponding degrees of dissociation are 44 and 22 per cent, re- 

 spectively. The discrepancy between the dissociation as de- 

 termined by the two methods, then, while relatively rather small 

 at first, increases enormously with the concentration within the 

 limits investigated. 



Zinc sulphate (Table 5) shows no dissociation according to 

 the freezing-point determinations when the solutions contain 

 a gram-equivalent or more of the salt per liter, and yet zinc 

 sulphate solutions have an electrical conductivity nearly the 

 same as that of the equivalent solutions of MgS0 4 (Table 1). 

 The most dilute solution represented in Table 5 yielded a molec- 

 ular weight of 117.4, corresponding to a dissociation of 38 

 per cent. ; the conductivity method yields about 40 per cent. 

 For the normal solution, where the dissociation is nil according 

 to the cryoscopic work, it is 24 per cent, according to the con- 

 ductivity. 



Manganous sulphate (Table 6) at first shows an increase of 

 molecular weight with the increase of concentration and then 

 a decrease. This also appears in the case of ZnS0 4 (Table 5) 

 though less markedly. Again CdSO* (Table 7) shows this 

 behavior in a marked degree, while NiS0 4 (Table 8), CoS0 4 

 (Table 9) and CuS0 4 (Table 11) show it slightly, and possibly 

 also FeS0 4 (Table 10). The electrical conductivity of MnS0 4 

 solutions increases regularly with the dilution, as does that of 

 solutions of all the other sulphates investigated. It is clear 

 that according to the conductivity determinations the dis- 

 sociation constantly increases with the dilution in the case of 

 2 



