VOLUME CHANGES IN THE PROCESS OF SOLUTION. 89 



traction per cc. of the original volume of A v = '000685 cc. 

 Similarly for acetone-alcohol, a v ='000842. These results 

 point to the conclusion that in mixtures of organic liquids 

 such as the above, in the preparation of which there is 

 practically no change in volume, the specific solution 

 volume of a solute lies between its values in the simple 

 solvents. It will be seen from the following tables that 

 this is not the case with solutions in water-alcohol mixtures. 

 In Table XVIII are given the specific solution volumes of 

 mercuric chloride in water, ethyl alcohol, and in a mixture 

 of alcohol and water, at 30° O. 



Table XVIII. 



Mercuric chloride. 



(a) In water (d = -997062). 



A d t v s 



2-1396 1-013096 -180 



3-6307 1-025072 -182 



(b) In ethyl alcohol (do = -780897). 

 7-2830 -830233 -160 



13-2739 -870108 -160 



22-9652 -933074 -162 



(c) In water-alcohol (d = -941605). 

 Alcohol = 33-17 per cent, (weight). 



2-8875 -963672 -196 



6-1069 -987959 -196 



7-0298 -994844 -197 



The solvent used in this case was prepared by mixing 

 88 # 1129 cc. of water with 55*7538 cc. of alcohol. The 

 resulting volume was 139*4110 cc, which corresponds to a 

 contraction of 4*4557 cc. or '03097 cc. per cc. of the original 

 volume. This contraction is about fifty times as great as 

 that observed in the case of benzene-alcohol or benzene- 

 acetone. 



