8 Mr. W. Sutherland on Ionization in Solutions 



with a similar meaning for A 2 . Then 



ein («i v i^i ~ ^2 V 2 ? ^)/^ 



. cZE v l v 1 A 1 ~\- n 2 v 2 A 2 



J?2 



'<fo 1 + 27r(Ai + A 2 )Cviv 2 {m(»i + «3)//ijV3KI\ 

 In the majority of experimental cases 



v 2 = 1, 7i 2 v 3 = n 1 v 1 = n 2j 



(9> 



and the coefficient of mud.Hj/dtt is the molecular specific con- 

 ductivity in electrostatic units in which e is measured 



*(Ai"hA 2 ) ' 



1 + 2ir (A a + A 2 ) C v±v 2 \ in {n x -t ji 2 ) / 7ip/3KIX ' 



At infinite dilution n — Q and 97 becomes t; the viscosity of 

 the pure solvent, i is assumed to become 1, and A, has the 

 value 



X = A 01 + A 03 (11) 



where 



1/^cAoi — faaji -j C ^V^ts-K^i^A + 1 /(I -I- c/«i 2 ) } e 2 v lm ( 1 2) 



Thus (11) expresses Kohlrausch's principle that the limiting 

 conductivity is the sum of two independent ionic conductivities 

 usually called ionic velocities. Noticing that Ai depends 

 upon 77 and upon quantities independent of concentration, we 

 write 



\w i 



\,7] u 1 + 27r(A! + A 2 ) Cvxv 2 { in (;,'! + n 2 )/h j */3KlA ' * 



4. Verification of the Equation by Representative Experimental 

 Data for Typical Solutions, and Proof that Ionization is 

 Almost Always Complete at all Concentrations. 



Years ago Kohlrausch discovered that for dilute aqueous 

 solutions X/X is linear in ni, as (13) shows it must be when 

 i = l in X and n is small. Since then he has neglected this 

 clue in pursuit of empirical expressions for i which might 

 express chemical equilibrium between ionized solute and that 

 not ionized. That in dilute solutions X is linear in m has 

 been shown by the recent measurements of Noyes & Coolidge 

 (Journ. Amer. Ohem. Soc. xxvi. 1901) for aqueous solutions 

 of NaCl and KC1 at temperatures up to 306° C. 



It appears from (13) that what has been called the degree 

 of ionization of a dilute solution i measured by X/a or 



