io8 



Conductivity of Aqueous Solutions. Part IV. 



at 281 and 306, owing to the possible effect of hydrolysis. The ioniza- 

 tion-values for magnesium sulphate at 100, 156, and 218 are therefore 

 to be regarded only as rough estimates, and those for potassium sulphate 

 and barium nitrate at 281 and 306 as possibly in error by several per cent. 



Table 27. The conductance ratio (100 A/A ) and approximate 



percentage ionization. 



With respect to the change of ionization with the concentration at any 

 definite temperature, it will suffice to recall that the functional relation 

 must be of a corresponding form to that between equivalent conductance 

 and concentration, which was discussed in section 42, and again to empha- 

 size the remarkable fact that the exponent in that function has nearly the 

 same value for di-ionic and tri-ionic salts, and a value, moreover, which 

 does not vary markedly with the temperature. Thus for the five substances, 

 potassium chloride, sodium chloride, silver nitrate, potassium sulphate, and 

 barium nitrate, at all temperatures between 18 and 306 inclusive, the 

 ionization (y) can be expressed by an equation C(l y) = const. X 

 (Cy) n , in which n has values varying only between 1.40 and 1.52. 



Assuming that the conductance-ratio may be regarded as at least an 

 approximate measure of the ionization, certain conclusions in regard to 

 the relation of the latter to temperature may be drawn from the results of 



