VOLUME CHANGES IN THE PROCESS OF SOLUTION. 87 



It will be noticed that Ad> is approximately constant up 

 to butyramide, but between this member and the next 

 there is a considerable increase in volume difference. This 

 variation for higher members of an homologous series is 

 common to most physical properties. 



Mixed Solvents. 



Determinations were also made of the solution volumes 

 of different solutes in solvents prepared by mixing two 

 liquids. Weighed quantities of the liquids were mixed and 

 the density of the mixture determined with a pyknometer 

 in the usual way. A weighed quantity of the solute was 

 then dissolved in a weighed quantity of the mixture, and 

 the density of this solution determined, and the specific 

 solution volume of the solute calculated in the usual way. 

 In the following table are given the solution volumes of 

 benzophenone in various solvents at 30° O. 



Table XVJI. 

 Solute —Benzophenone. Temp. 30 C. 

 (a) Solvent — Benzene (d = -868327). 





A di i-> s 

 1-5067 -871189 -897 

 4-2746 -876398 -893 

 12-4329 -890517 -892 





(b) Solvent— Acetone {d = -781169). 



3-6851 -790169 -870 



7-5410 -798813 -872 



11-9758 -808462 -873 





(c) Solvent— Ethyl alcohol (d = -780897). 



7-7015 -798935 -876 



11-8189 -807776 -877 



(rf) 



Solvent — Benzene- Acetone, Acetone = 50*72% (weight) 

 d = -822244. 

 5-8368 -835038 -878 

 12-9402 -848865 -883 



w 



Solvent — Alcohol-Acetone, Acetone = 56-36% (weight) 

 d = -781568. 

 10-1467 -804867 -877 

 13-2029 -811255 -878 



