Studies in Chromium Arsenate Sol. Part III. Changes in Extinction, pH and Electrical Conductance of the Sol During Coagulation at Different Stages of Dialysis

A study of the influence of K2SO4 on the colloidal solution of chromium arsenate by light extinction method reveals that coagulation is accelerated with increasing amount of electrolyte until at a certain concentration it is maximum. Higher concentrations than this give rise to loose aggregation. The pH of the sol increases with increasing amounts of K2SO4. This is notlimited up to the coagulation point but goes on even beyond it. The electrical conductance of the sol itself decreases continuously with addition of the electrolyte. The structure of the sol particles and the changes taking place during their coagulation have been discussed on the basis of the observations of extinction, gal and electrical conductivity