on the Fluidity of Mixtures of Miscible Liquids. 665 



number of liquids, so that in a liquid mixture it is assumed 

 that 



£1 

 io 1 



iv 2 



IVn ' 



where i^... is the specific volume taken up by the constituent 

 in the mixture, and 

 w l . . . is the co-volume of the constituent. 



For this assumption to be true, all liquids, non-associated 

 and chemically indifferent, which have the same ratio of 

 v to w at the same temperature, should undergo no volume 

 change on mixing, and the fluidities of mixtures of the two 

 liquids should be given by the formula 



100 vF = m l v i F 1 + m 2 v 2 F 2 . 



Carbon tetrachloride and benzene are two such liquids. 

 Batschinski's formula for carbon tetrachloride is 



for benzene it is 



therefore 



t7-0*5782 = 0'000475F ; 



i>-l*0476=0-000581F; 



wx 0-5782 



w 2 ~ 1-0476 



= 0*552. 



The following table gives the ratio of vcci 4 to ^c 6 h 6 for 

 temperatures from 10° C. to 70° 0.:— 



Temperature. 



V CC1 4 . 



V C B H 6 . 



V ll V 2' 



10° C. 



0-6199 



1-1242 



0-552 



20 



0-6274 



1-1377 



0-552 



30 



0-6350 



1-1514 



0-552 



40 



06428 



1-1661 



0552 



50 



0-6510 



1-1812 



0-551 



60 



0-6594 



1-1966 



0-551 



70 



06683 



1-2124 



0-551 



It follows that the ratio of v to w is the same for carbon 

 tetrachloride and benzene at all temperatures from 10° C. to 

 70° C, and there should be no change in volume on mixing 

 these two liquids. 



Thorpe and Rodger found a very slight contraction, 

 decreasing with rise of temperature. 



Again, the fluidities found for mixtures between 10° C 



