70 



IONIZATION OF COMPLEX 



obtained from the few available observations. In some cases 

 also Kohl rausch's a observation may be utilised, viz., that the 

 curves obtained by plotting equivalent conductivity against 

 linear concentration (i.e., the cube root of the concentration), 

 are for univalent salts, through considerable ranges, practically 

 rectilinear. 



The dilution-ionic-concentration curves, having been drawn 

 for the simple solutions (curve A for electrolyte ], and B for 2, 

 in the figures below), the problem resolve itself into finding two 

 points, one on each curve, having, according to equation (1), the 

 same abscissa, and having ordinates which satisfy the condition 

 of equation (2). This may be done of course by inspection, 

 but more accurately, and usually more quickly, by one or other 

 of several graphical processes. 



(1.) Plot a new curve 

 C (Fig. 1) with the 

 same abscissae as A 

 and B, but with ordi- 

 nates equal to the sum 

 of Nj times the ordi- 

 nates of A and N 2 

 times the ordinates of 

 B. Then draw the 

 straight line F G par- 

 allel to the axis of 



, . ionic concentrations 



3"' and at a distance 



unity from it (I assume for simplicity that the dilutions and 

 ionic concentrations have been plotted to the scale unity). Let 

 F G cut C in G ; and through G draw the straight line G J par- 

 allel to the axis of dilutions and cutting A and B in I and H 

 respectively. I and H are the two points required. For they 

 have the same abscissa O J, and their ordinates, I J and H J, 

 are such that 



N x . 1 J + N 2 . HJ = GJ = 1. 



Then a r =OJ . IJ, and 4 a 2 = OJ.HJ. 



'Wied. Ann., 26, 201, 1885. 



