Sodium-alizarin-3-sulphonate as a colloidal electrolyte

Summary During the study of the composition of metal chelates of sodium alizarin-3-sulphonate, it was realized that the colloidal nature of the reagent, especially in concentrated solutions, masks the true composition of the chelate. An investigation of the electrical conductance at various dilutions and temperatures shows that the reagent belongs to the class of colloidal electrolytes. It is recommended that for the study of the composition of chelates involving such chelating agents, extremely dilute solutions should be employed for physicochemical investigation, because under these conditions the reagent would behave as a true electrolyte.