and the Anomaly of Strong Electrolytes. 137 



a 2 

 That is, ,-, ,, T = K X 2*'~\ 



(1 — a)\ 



if the mean velocities do not vary sensibly from one element 

 of volume to another. 



Again, 2r=Vi, 



and /. _^. V =KV-* 



K. 



(1-«)V* 

 Rudolphi proposed the empirical relation 



..2 



(l-a)V 



and found it to hold with very considerable accuracy. 

 This can be written 



7 -^ w =KV- i =Kr-!=K,4/r*=K J Xx A ; 



(1 — a)V rra r 2 * 



and from this it is clear, by comparison with equation (A), 

 that if the interionic force varies inversely as the square of 

 the distance, theu the force causing ionization of the mole- 

 cules varies inversely as the fifth power of the distance. 

 Van't Hoff found the relation, 



__^ 7? = constant, 



to hold with very satisfactory accuracy for various strong 

 electrolytes. This may be written 



(v) x ( v J / V = constan ^- 



Now some pairs of dissimilar ions will at a given instant 

 be approaching, and the remainder separating. If it is only 

 the approaching ions which produce molecules, then clearly 

 the effective concentration of ions must be less than the total 



concentration of ions. That is, the concentration term I .. ) 



must be replaced by a smaller one. In the above relation 



l^f) is substituted, instead of I , T J , empirically. 



