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 : 



i2 



K = 





(^-£) 



V 



where K is the dissociation-constant, Mu is the molecular con- 

 ductivity at dilution V and ix^ 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 /i„ = — , 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 



^^L 1.037 X 10-2 \ /1.037 X 10-2 V 



K[l -, j r- X ]= m\ -, . r— X ) 



\ m{u-\- v) J \ miu-t v) / 



which reduces to 



1.037 X 10-2 1 075 X 10-4 



m = -. X -\ „, . x^. (i) 



u + V K[u + vy 



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^ = k {m — c). 



Now 1.037 X 10-2 X = {u + v) c; hence 



1.037 X 10-2 



c = 1 ; 



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



220 



