Section p/. Ionization of the Substances. 



271 



fraction of the salt which dissociates according to the three reactions 



KHS0 4 = K + + HS0 4 ", 



KHS0 4 = K 4 + IP + S0 4 = , and 



2KHS0 4 = 2K + -f S0 4 ~ -f H,S0 4 



respectively,* it is evident that 



A =y x ( Ak + Ahso 4 ) + y 2 (AK + Ah + 2A s o 4 ) + y 3 ( A K + Aso 4 ) 

 or, putting y = y x -f y 2 -f y 3 , that 

 A = y(AK + Ahso 4 ) -f-y 2 (Ah + 2A S o 4 Ahso 4 ) + y 3 (Aso 4 Ahso 4 ). 

 Now the two limiting values of y 3 are zero and y y 2 (when y x = o), 



whence it follows that 



A y (Ak + Ahso 4 ) 



r*< 



(Ah + Aso 4 ) + (Aso 4 Ahso 4 ) 



and y 2 ^> 



A y ( Ak -f- A s o 4 ) 



Ah -f- Aso 4 



Limiting values of y 2 , the fraction dissociated into hydrogen-ion, can 

 be calculated in this way from the data presented in this monograph with 

 the help of the assumptions that the un-ionized fraction (1 y) of the 

 salt has the same value as in the case of other salts of the uni-univalent 

 type at the same concentration and temperature, and that the equivalent 

 conductance of the hydrosulphate-ion is the same as that of the acetate 

 ion at the same temperature. Table 117 contains the results of these 

 calculations f for four concentrations at 18, 100, and 156. 



*The dissociation according to the reactions 2KHSO<=: K=S0 4 + H+ -f- HS(V and 

 2KHS04 = K=S0 4 -(-2H+-)- S0 4 = is neglected in this preliminary calculation; but 

 the KzSOi formed must be small in most cases owing to the small concentration of 

 sulphate-ion. 



fThe data used are as follows : 



The values of A are copied from table 108. Those of 7 are the mean ionizations 

 for potassium and sodium chlorides as given in table 12, Part 11. 



