676 



IONIC RADIUS AND IONIC EFFICIENCY 



anions on the rate of diffusion of water from pure water into the 

 solution through a negatively charged membrane increases in the 

 order I > Br > CI, the accelerating influence of the I ion being the 

 greatest. 





•f— ( 



to 



.T-« 



-a 



G) 



240 



220 

 200 



180 



160 



140 



120 



100 



80 



60 



40 



" 20 







1024 512 256 128 64 32 16 8 4 2 "^ 



Concentration of salt solution 



Fig. 2. The same as Fig. 1 except that the solutions and water are alkaline 

 (pH about 11.0). 



The same is true when the solution is more alkaKne. Thus in 

 Fig. 2 NaCl, NaBr, and Nal were dissolved in a n/ 1,000 solution 

 of KOH instead of in pure water and the outside solution was n/1,000 

 KOH. The sign of charge of the membrane remained negative, 

 however, and therefore the relative efficiency of the three anions 



