74 G. J. BURROWS. 



VOLUME CHANGES IN THE PROCESS OF SOLUTION. 

 By George Joseph Burrows, b.Sc 



(Communicated by Prof. 0. E. Fawsitt.) 



[Bead before the Royal Society of N. S. Wales, August 6, 1V19~\ 



A considerable amount of work has been recorded on the 

 changes in volume which take place in the formation of 

 solutions. When a solid is dissolved in a liquid, or when 

 two liquids are mixed, the volume of the resultant solution 

 is found in most cases to differ from the sum of the original 

 volumes of the constituents. We cannot state how far this 

 is due to a change in the volume of the solute and how far 

 to the solvent. For the sake of convenience it is customary 

 to assume that the volume of the solvent is unaltered 

 by the process of solution, and to attribute any change 

 in the volume of the system to the solute. In this way 

 the volume of a solute in a solution may be determined. 



Thus if A represents the weight in grams of solute dis- 

 solved in 100 grams of solvent, 

 d = the density of the pure solvent, 

 di = the density of the solution, 

 and v s = the specific solution volume of the solute, 



' /100 + A 100 \ . A m 



then, v s — -! — — + A (I> 



\ di do / 



or if <f> = the molecular solution volume of the solute, 



then,* = *±JL-iL (II> 



di do 



where g = the weight in grams of solvent containing the 

 molecular weight (M) in grams of solute. 



By employing the above formulae Tyer 1 and Dawson 2 

 have shown that the specific (or molecular) solution volume 



1 J.C.S., (1910) 97, 2620. 2 Ibid., 1896. 



