CHAPTER X 



THE ELECTRICAL CONDUCTIVITY OF SOLUTIONS OF PROTEIN 



SALTS 



1. The Influence of Dilution upon the Conductivity of Solu- 

 tions of Protein Salts. The Ostwald dilution-law for a binary 

 electrolyte is usually formulated as follows : 



(-) 



where K is the dissociation-constant, fi v is the molecular con- 

 ductivity at dilution V and /^ is the molecular conductivity 

 at infinite dilution, that is: 96.44 (u + v) where u and v are 

 average equivalent migration velocities in centimetres per 

 second under unit potential gradient, of the cations and anions 

 respectively. 



Now fjL v = , where x is the specific conductivity in reciprocal 



ohms, and m is the equivalent concentration, i.e., y ; hence from 

 the above equation we have 



_/- 1.037 X 10- 2 \ /1.037 X 10- 2 V 



K[l 7 ; r-X] = mi 7 ; r X] 



\ m (u + v) I \ m (u + v) / 



which reduces to 



1.037 X 10- 2 . 1.075 X 10- 4 2 ,.. 



m = ; X H ^r-f : rr~ X*. (l) 



U + V K(U + V) Z 



The same formula can be derived as follows (8); let c be the 

 equivalent concentration of the ions, m and K having the same 

 significance as before; then, applying the mass law, we have 



C 2 = k (m - c). 



Now 1.037 X lO- 2 x = (u + v) c; hence 

 _ 1.037 X 10- 2 



u + v 



substituting in the above equation we regain equation (i). 



220 



