58 



Properties of Liquid Mixtures. 



middle of the range, but in the case of alcohol and benzene 

 disagree totally at the extrem3 percentages. 



Alcohol and Benzene. 



K. 



010 



0-30 



050 



0-70 



090 



1 SPk 



0-67 

 031 



019 

 016 



0-27 

 034 



031 

 046 



040 



0-82 



Pa d? 



l-SdPB 



Pb d? 



Alcohol and Toluene. 



1. 



010 



0-30 



050 



070 



0-90 



1 d?A 



061 



054 



023 

 0-22 



021 



025 



027 

 0-27 



062 

 070 



P^ dS 

 i-Sd/> B 



Pb d? 



It has already been mentioned that Linebarger states the 

 conclusion that the partial pressure of benzene and toluene in 

 mixtures is simply proportional to the molecular percentage 

 present ; this conclusion appears to be only roughly true. 

 According to the results expressed by the curves on fig. 2 

 no such simple relation holds ; the partial pressures of these 

 hydrocarbons being as far from linear as that of the carbon 

 tetrachloride with which they are mixed. 



Linebarger proceeds to apply his conclusion to determine 

 the molecular weight of acetic acid, in mixtures of the acid 

 with benzene and toluene. 



For in any mixture the partial pressure of the hydrocarbon 

 » B divided by the pressure of the pure liquid 7r B gives, accord- 

 ing to this rule, the true molecular fraction of hydrocarbon 

 present, say 1 — ?'? whilst 1 — f is that calculated from the 

 formulae C 6 H 6 (or C 7 H 8 ) and CH 3 COOH, or 



whence 



x , =r/(i-«')=(TB-^)/^ ) 



where x 1S the ^ rue ra ^° °f the number of molecules of acetic 

 acid to molecules of hydrocarbon. If this be divided into the 



