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LXXI. yote on the Abnormality of Strong Electrolytes. 

 By David Leonard Chapman and Herbert John 

 George *. 



IN a series of papers recently published in the ' Journal of 

 the Chemical Society ' (Trans. Chem. Soc. cxiii. pp. 449, 

 627, 707, and 790 (1918)) J. C. Ghosh has endeavoured to 

 explain the anomalous behaviour of strong electrolytes. 

 From his theory the electrical conductivities and the osmotic 

 pressures of solutions of salts can be deduced, and the values 

 thereby calculated for the ranges of concentration examined 

 are in good agreement with the experimental results. This 

 theory has attracted much attention, and on the whole has 

 been favourably leceived, although also it has been sub- 

 jected to a searching adverse criticism from several points of 

 view by J. R. Partington (Trans. Far. Soc. xv. p. 98 (1919)). 

 For a deductive theory it embodies an unusually large 

 number of assumptions. Thus the author postulates that 



(1) the dissolved salt is completely ionized ; 



(2) the mean disposition of the charged ions is regular, 



and similar to the arrangement of the atoms when 

 they assume a crystalline structure ; 



(3) the component ions of a salt molecule form a com- 



pletely saturated electrical doublet, and the work 

 necessary for separating the component ions of* a 

 molecule is the electrical work, A, done in moving 

 the ions constituting a doublet from their fixed 

 mean distance in the solution to an infinite distance 

 apart ; 



(4) the free ions (conducting ions) are those whose 



kinetic energy is greater than the work to be done 

 in separating them to an infinite distance. 



In addition to these the author makes other implicit and 

 stated assumptions which it is not necessary to specify here. 



Our present purpose is merely to indicate what appears to 

 us to be a false deduction from the postulate (4) quoted 

 above, and to show that, if the proper correction is made, 

 the theory in its present form fails to account for the facts. 

 It is sufficient to consider the simplest case to which the 

 theory has been applied — namely, that of a uni-univalent 

 salt such as potassium chloride. According to Ghosh, it 

 follows, in this case, from postulate (4) that the kinetic 



A 



energy of a free ion must exceed 5, i. <\, half the work 

 * Communicated bv the Authors. 



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