80 PROPERTIES OF ELECTRICALLY CONDUCTING SYSTEMS 



of m of only 1.18. Correspondingly, resorcinol in hydrobromic acid has 

 a constant of only 1.40, which is distinctly lower than that of other sub- 

 stances dissolved in this solvent. It is interesting to note that the value 

 of the constant m never exceeds 2. The highest value of this constant is 

 1.80 for methyl and ethyl alcohols in hydrobromic acid. It appears prob- 

 able that the values of m for these two substances in hydrogen iodide 

 will be found greater than in hydrogen bromide. 



In fused mercuric chloride the different typical salts exhibit a very 

 similar behavior. The constant P differs only inappreciably for different 

 electrolytes and the values of the constant m, for the most part, fall 

 within very narrow limits. 



In the amines the constant m increases and the constant P decreases 

 as the organic radical becomes more complex. The same is true in the 

 case of acetic and propionic acids, where the constant m for propionic 

 acid is much greater than for acetic acid. Judging by the relatively low 

 value of the constant m for liquid iodine, this substance is a fairly good 

 ionizing agent. 



2. Geometrical Interpretation of the Conductance Function. The 

 conductance function: 



Y 



may be interpreted most readily by graphical methods. It will be under- 



stood that y = T and that the following equations may at once be con- 

 A 



verted to equations in which CA and A appear as variables in place of 

 CY and Y- In speaking of the ionization, it is not intended to convey the 

 impression that the conductance ratio necessarily measures the ioniza- 

 tion, but rather it is introduced as a convenient variable for the purpose 

 of discussion. If we differentiate the above equation, we have: 



(15) ____ , 



'' d(Cy) 



dv 



The coefficient , * ., which is the tangent to the Y> CY-curve, is a 



measure of the change of the ionization as a function of the ion concen- 

 tration at any point on the curve. It is evident that if the term 



~ .. . approaches zero as CY approaches zero, the tangent will ap- 

 proach the value ^ as a limit, where K is the limit which K' ap- 



