TOLMAN. — ELECTROMOTIVE FORCE PRODUCED IN SOLUTIONS. 133 

 TABLE II. — Continued. 



partial volumes of potassium, sodium, lithium, and hydrogen iodides 

 in molal solution, as calculated from existing data. 



The partial volume for any solute may be determined from succes- 

 sive weighings of a picnometer filled with solutions of diflerent con- 

 centrations. Let V be the volume in com. held by the picnometer, 

 and let it contain 31 gm. of solution when the percentage concentration 

 of the solute in question is P X 100, and M' gm. of solution of concen- 

 tration P' X 100. The amount of solvent in the picnometer when it is 

 weighed containing solution of concentration P is (l—P) M, hence 

 the volume of a solution of concentration P' containing the same 



amount of solvent would be r ,J ^r, ^^» and the amount of the 



{I — P) M' 



solute in that solution would be 



(1 - P) M 



relation 



{I- P')M 



-,P'M' leading to the 



{l-P)M 



^v _ (l-P')31 



,v-y 



Am 



(l-P)M 



(1-P')3I' 



-P'3I'-P3I 



{\-P)3IV-{\-P')3rV 

 (1 - P)3IP'3I' - (1 - P') 3rP3I 



(3) 



It is evident that the percentage accuracy in the determination of 

 this quantity Ay/ Am will be greater the greater the quantities Ay and 



